A multi-stage industrial wastewater reuse system

Abstract

The application discloses an industrial wastewater multistage recycling system, comprising a desalted water treatment module, a deep water treatment module and a cooling water treatment module which are connected with each other; wherein the desalted water treatment module comprises a raw water tank, a first RO system, an intermediate water tank, a second RO system, a micro-vortex clarifier and a clarified water tank; the output end of the raw water tank is connected with the input end of the intermediate water tank and the input end of the second RO system in sequence; the output end of the first RO system is connected with the input end of the micro-vortex clarifier and the input end of the deep water treatment module; the output end of the second RO system is connected with the input end of the raw water tank, forming a water supplementing circulation system; and the output end of the micro-vortex clarifier is connected with the input end of the clarified water tank and the input end of the deep water treatment module. The multistage recycling system is used for treating lead-zinc smelting water, realizes multistage recycling of the treated water and improves the recycling rate of the water.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metallurgical water treatment, and more particularly to an industrial wastewater multi-stage recycling system. BACKGROUND

[0002] Industrial wastewater is inevitably generated in the lead-zinc smelting process, and common examples include equipment cooling circulating water, domestic sewage, boiler blowdown water, primary concentrated water generated in desalted water preparation, and waste acid generated in the acid production system, among which the equipment circulating cooling water and the primary concentrated water generated in desalted water preparation have a large water volume.

[0003] In the prior art, the primary concentrated water generated by the desalted water treatment module is discharged as industrial wastewater by some enterprises, and is treated and then recycled by most enterprises. Common industrial wastewater treatment methods include physical and chemical methods, electrochemical methods, biological methods, membrane separation methods, and other treatment methods. After treatment, the wastewater is treated using different process units according to the water quality. The desalted water production process uses a pretreatment + two-stage reverse osmosis process. The primary concentrated water is discharged to a deep water treatment station for treatment. The primary water is fed into an intermediate water tank and then fed into a two-stage RO system. The produced water is used as boiler feed water. The concentrated water is returned to the original water tank. The deep water treatment station uses a pretreatment + multi-stage filtration + ultrafiltration + two-stage reverse osmosis process. The produced water on the fresh water side is mixed with new water and then supplied to various user points as production water. The concentrated water on the waste water side is sent to a waste acid and wastewater system for treatment. The produced water is used as desalted water raw water or as a new water source for a circulating water pool. The water recycling rate is relatively low, and multi-stage recycling cannot be achieved.

[0004] In addition, in the prior art, the desalted water treatment module has relatively poor water quality. After a long period of operation, the desalination efficiency of the reverse osmosis membrane has been greatly reduced. The primary concentrated water from the first-stage reverse osmosis has poor water quality due to hard water, enrichment of electric conductivity and heavy metal ions, resulting in a decrease in the first-stage reverse osmosis water production rate year by year. The amount of primary concentrated water discharged is increasing, and a certain amount of desalted water requires more new water, which will discharge more industrial wastewater.

[0005] Secondly, the pretreatment operation of the wastewater deep treatment is unstable, resulting in unqualified pretreatment produced water. When the unqualified pretreatment produced water enters the backend, it causes the pressure difference of the ultrafiltration membrane and the reverse osmosis membrane to increase, which requires frequent cleaning, reduces the water production rate, reduces the service life of the reverse osmosis membrane, and increases the cost of cleaning chemicals, resulting in an increase in the overall operation cost. The produced water from the deep water treatment is used as new water by various user points, as equipment cooling circulating water, and as desalted water raw water. The water recycling rate is relatively low, and multi-stage recycling cannot be achieved.

[0006] Therefore, it is of great significance to provide an industrial wastewater treatment system that can achieve multi-stage recycling. SUMMARY

[0007] Therefore, the industrial wastewater multi-stage recycling system and method provided by the application not only has simple system design and easy operation, but also realizes multi-stage recycling of treated water and improves water recycling rate.

[0008] To achieve the above object, the application adopts the following technical scheme:

[0009] The industrial wastewater multi-stage recycling system comprises a desalted water treatment module, a deep water treatment module and a cooling water treatment module which are connected with each other.

[0010] The desalted water treatment module comprises a raw water tank, a first RO system, an intermediate water tank, a second RO system, a micro-vortex clarifier and a clarified water tank.

[0011] The output end of the raw water tank is connected with the input end of the first RO system, the input end of the intermediate water tank and the input end of the second RO system in sequence.

[0012] The output end of the first RO system is connected with the input end of the micro-vortex clarifier and the input end of the deep water treatment module.

[0013] The output end of the second RO system is connected with the input end of the raw water tank, forming a first water supplementing circulation system.

[0014] The output end of the micro-vortex clarifier is connected with the input end of the clarified water tank and the input end of the deep water treatment module.

[0015] The output end of the cooling water treatment module is connected with the input end of the micro-vortex clarifier and the input end of the deep water treatment module, the output end of the clarified water tank is connected with the input end of the cooling water treatment module, and the output end of the deep water treatment module is connected with the input end of the intermediate water tank.

[0016] The industrial wastewater multi-stage recycling system designed by the above technical scheme changes the destination of the first concentrated water in the desalted water treatment module, and the first concentrated water generated by the desalted water treatment module is used as water supplement for the subsequent cooling water treatment module after being treated by the micro-vortex clarifier, so that new water is no longer needed to be added, and the micro-vortex clarifier will regularly discharge sewage to the deep water treatment module, greatly reducing the load of the deep water treatment station.

[0017] Further, the deep water treatment module comprises a deep water adjusting tank, a deep water stirring tank, a mechanical stirring clarifier, a deep water membrane treatment system and a production water tank.

[0018] The output end of the micro-vortex clarifier, the output end of the first RO system and the output end of the cooling water treatment module are connected with the input end of the deep water adjusting tank.

[0019] The deep water adjusting tank output end is connected with the deep water stirring tank, the mechanical stirring clarifying tank, the deep water membrane treatment system and the production water tank input end in sequence.

[0020] The production water tank output end is connected with the cooling water treatment module and other user input end.

[0021] The production water tank output end is connected with the raw water tank input end, forming a second water replenishing circulation system.

[0022] The mechanical stirring clarifying tank output end is connected with the deep water adjusting tank input end.

[0023] The deep water membrane treatment system output end is connected with the cooling water treatment module input end.

[0024] The deep water membrane treatment system output end and external water source are connected with the production water tank input end respectively.

[0025] The above technical solution ensures that the water from the deep water membrane treatment system is qualified water, and ensures that the deep water production index is stable and sustainable. The water in the production water tank is used as production water to enter the raw water tank, reducing the addition of new water and saving resources.

[0026] Preferably, the cooling water treatment module comprises a device cooling circulating water tank, a cooling water system and a hot water tank.

[0027] The production water tank output end is connected with the device cooling circulating water tank input end.

[0028] The device cooling circulating water tank output end is connected with the cooling water system and the hot water tank input end in sequence.

[0029] The cooling water system output end is connected with the deep water adjusting tank input end.

[0030] The above technical solution continues to deliver the circulating water with poor water quality in the device cooling circulating water tank to the deep water adjusting tank for further water treatment, producing qualified water for use, reducing the addition of new water and reducing resource waste.

[0031] Preferably, it further comprises a water quality stable circulation water supply system, wherein,

[0032] The micro-vortex clarifying tank output end is connected with the clarifying water tank, the device cooling circulating water tank, the cooling water system, the hot water tank and the micro-vortex clarifying tank input end in sequence.

[0033] The technical scheme realizes that the equipment cooling circulating water pool and the micro-vortex clarifier form a circulating water supply system, and the water quality of the equipment circulating water is stable; the water flow direction is: micro-vortex clarifier water pool→equipment cooling circulating water pool→equipment cooling water system→equipment cooling circulating water pool hot water pool→micro-vortex clarifier→micro-vortex clarifier water pool.

[0034] Preferably, the deep water film treatment system output end is connected with the intermediate water tank input end to form a water production circulating system.

[0035] The technical scheme changes the water production direction of the deep water treatment module, and the water production is directly pumped to the intermediate water tank, mixed with the primary water production of the desalted water treatment module, and the index is better than that of the primary water production.

[0036] Preferably, a pH and turbidity on-line monitor is arranged between the mechanical stirring clarifier and the deep water film treatment system.

[0037] The technical scheme ensures the water quality of the final water production and the continuous stability of the deep water production index by arranging the pH and turbidity on-line monitor, qualified water entering the deep water film treatment system, and unqualified water returning to the deep water adjusting pool.

[0038] Further, the mechanical stirring clarifier comprises a pool body, a water inlet pipe, a water outlet pipe, a cover body, a fixing frame, a hollow cylinder, a sludge concentration chamber, a motor and a plurality of dosing pipes.

[0039] The motor is fixed at the top end of the pool body, the motor bottom end is fixedly connected with a stirring shaft, the stirring shaft penetrates through the top end of the pool body, a fixing frame, a stirrer and a mud scraping plate are fixed on the stirring shaft from top to bottom, the fixing frame bottom end is fixedly connected with the cover body top end, the hollow cylinder is fixedly connected with the stirring shaft and located inside the cover body, the hollow cylinder top end and bottom end are provided with openings, the stirrer is located inside the hollow cylinder, the mud scraping plate is located below the cover body, and a plurality of water collecting grooves are arranged on the fixing frame.

[0040] The water inlet pipe penetrates through the pool body side wall and communicates with the hollow cylinder inside, and the water outlet pipe penetrates through the pool body side wall and communicates with the water collecting groove.

[0041] The sludge concentration chamber is fixed at the bottom end of the pool body and located below the mud scraping plate, and the sludge concentration chamber is connected with a blowdown pipe to communicate with the outside.

[0042] The plurality of dosing pipes are fixedly connected with the pool body top end.

[0043] Further, the hollow cylinder inside is a first reaction chamber, the cover body inside is a second reaction chamber, and the cover body outside is a separation chamber.

[0044] Preferably, the plurality of dosing pipes are in communication with the first reaction chamber, the second reaction chamber and the separation chamber respectively.

[0045] By using the above technical scheme, the primary thick water is treated by the mechanical stirring clarifying tank, the solid-liquid separation effect is improved, and the water quality of the produced water is improved.

[0046] Preferably, the stirring shaft rotation speed is 400-800 r / min.

[0047] By using the above technical scheme, the rotation speed of the stirrer is controlled according to the size of the water inflow, and the operation stability is improved.

[0048] The industrial wastewater multi-stage recycling system designed according to the application has the following technical effects:

[0049] (1) The primary thick water recycling system reflects the unity of comprehensiveness, completeness and practicability as a whole, and the water treatment technology is closely combined with reasonable recycling, which breaks the original water treatment process. According to the characteristics and current situation of the water resources in the factory area, a set of water resource recycling system is gradually formed, so that the primary thick water can be recycled according to the demand, quality, flow and multi-stage, and the efficiency of water resource recycling is improved. Taking the primary thick water resource as the main line, the treatment method combining industrial treatment and ecological purification is beneficial to promote the improvement of water environment, and a large-scale water resource recycling system is effectively formed.

[0050] (2) A variety of new water sources are developed by using the primary thick water as a supplement, and a variety of recycling ways are formed at different levels, basically forming a closed loop of multi-stage recycling of regenerated water, which greatly improves the regional water resource reuse rate. Taking the primary thick water resource as the main line, the treatment method combining industrial treatment and ecological purification is beneficial to promote the improvement of water environment;

[0051] (3) A scientific system of water resource recycling is constructed, and the production and application of regenerated water are diversified, so that the primary thick water recycling becomes an important support for regional water resources.

[0052] (4) After the project of improving water recycling rate is successfully implemented, the treatment capacity of the deep water membrane treatment section is effectively improved, the water production index (the water production index is between PH value 7-9, conductivity < 50 us / cm, and hardness < 20 umol / L) is improved, which is much better than the first water production index of the desalted water treatment module, and the target of directly supplying the deep water to the intermediate water tank of the desalted water treatment module is achieved; for the desalted water module, since the deep water is directly supplied to the chemical water intermediate water tank, the use amount of fresh water of the desalted water module is greatly reduced, the primary concentrated water discharge amount is reduced, the start-up time of the chemical water pretreatment system and the first reverse osmosis is reduced, and a large amount of cost is saved. BRIEF DESCRIPTION OF DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute a part of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on the provided drawings.

[0054] Figure 1 It is a schematic diagram of the industrial wastewater multi-stage recycling system of the embodiment of the present application.

[0055] Figure 2 It is a structural schematic diagram of the mechanical stirring clarifier of the embodiment of the present application.

[0056] Figure 3 It is a structural schematic diagram of the micro-vortex clarifier of the embodiment of the present application.

[0057] In the drawings, 1 is a tank body, 2 is a motor, 3 is a stirring shaft, 4 is a fixing frame, 5 is a water outlet pipe, 6 is a cover body, 7 is a hollow cylinder, 8 is a mud scraping plate, 9 is a sludge concentration chamber, 10 is a blowdown pipe, 11 is a water inlet pipe, 12 is a second reaction chamber, 13 is a separation chamber, 14 is a water collecting tank, 15 is a stirrer, 16 is a first reaction chamber, 17 is a dosing pipe, 18 is a float ball stirrer, 19 is a hollow cylinder two, 20 is a water inlet pipeline, 21 is a sludge discharge pipeline, and 22 is a baffle bin. DETAILED DESCRIPTION

[0058] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments only constitute a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0059] As shown in the accompanying drawings Figure 1-2As shown, the application provides an industrial wastewater multi-stage recycling system, comprising a desalted water treatment module, a deep water treatment module and a cooling water treatment module connected with each other; wherein,

[0060] The desalted water treatment module comprises a raw water tank, a first RO system, an intermediate water tank, a second RO system, a micro-vortex clarifier and a clarified water tank.

[0061] The output end of the raw water tank is connected with the input end of the first RO system, the intermediate water tank and the second RO system in sequence.

[0062] The output end of the first RO system is connected with the input end of the micro-vortex clarifier and the deep water treatment module.

[0063] The output end of the second RO system is connected with the input end of the raw water tank, forming a first water supplementing circulation system.

[0064] The output end of the micro-vortex clarifier is connected with the input end of the clarified water tank and the input end of the deep water treatment module.

[0065] The output end of the cooling water treatment module is connected with the input end of the micro-vortex clarifier and the deep water treatment module, the output end of the clarified water tank is connected with the input end of the cooling water treatment module, and the output end of the deep water treatment module is connected with the input end of the intermediate water tank.

[0066] The industrial wastewater multi-stage recycling system designed by the above technical scheme changes the destination of the first concentrated water in the desalted water treatment module, and the first concentrated water generated by the desalted water treatment module is partially treated by the micro-vortex clarifier, and the water quality thereof meets the water quality requirements of users such as the circulating water pump house of the sulfuric acid plant and the circulating water pump house of the air compressor of the power plant as shown in Table 1, and is used as the water supplement of the subsequent cooling water treatment module, without the need to add new water, thereby reducing the use amount of new water at each user point, reducing the treatment amount of industrial wastewater, and the micro-vortex clarifier regularly discharges sewage to the deep water treatment module, greatly reducing the load of the deep water treatment station.

[0067] Table 1

[0068]

[0069] In this embodiment, the deep water treatment module comprises a deep water adjusting tank, a deep water stirring tank, a mechanical stirring clarifier, a deep water membrane treatment system and a production water tank.

[0070] The output end of the micro-vortex clarifier, the first RO system and the cooling water treatment module is connected with the input end of the deep water adjusting tank.

[0071] The output end of the deep water adjusting tank is connected with the input end of the deep water stirring tank, the mechanical stirring clarifier, the deep water membrane treatment system and the production water tank in sequence.

[0072] The production water tank output end is connected with the cooling water treatment module and other user input ends;

[0073] The production water tank output end is connected with the raw water tank input end, forming a second water replenishment circulation system.

[0074] The mechanical stirring clarifier output end is connected with the deep water adjusting tank input end.

[0075] The deep water membrane treatment system output end is connected with the cooling water treatment module input end.

[0076] The deep water membrane treatment system output end and the external water source are respectively connected with the production water tank input end.

[0077] The above technical solution ensures that the water from the deep water membrane treatment system is qualified water, ensures that the deep water production water index is stable and continuous, and the water in the production water tank is partially used as production water to enter the raw water tank, reducing the addition of new water and saving resources.

[0078] In the embodiment, the cooling water treatment module includes a device cooling circulating water tank, a cooling water system, and a hot water tank.

[0079] The production water tank output end is connected with the device cooling circulating water tank input end.

[0080] The device cooling circulating water tank output end is sequentially connected with the cooling water system and the hot water tank input end.

[0081] The cooling water system output end is connected with the deep water adjusting tank input end.

[0082] The above technical solution continues to deliver the circulating water with poor water quality in the device cooling circulating water tank to the deep water adjusting tank for further water treatment, producing qualified water for use, reducing the addition of new water, and reducing resource waste.

[0083] In the embodiment, a water quality stable circulation water supply system is further included, wherein,

[0084] The micro-vortex clarifier output end is sequentially connected with the clarifier water tank, the device cooling circulating water tank, the cooling water system, the hot water tank, and the micro-vortex clarifier input end.

[0085] The above technical solution realizes the formation of a circulation water supply system between each device cooling circulating water tank and the micro-vortex clarifier, and realizes the stability of the device circulating water quality; the water flow direction is: micro-vortex clarifier water tank → device circulating cooling water tank → device cooling water system → device cooling circulating water tank hot water tank → micro-vortex clarifier → micro-vortex clarifier water tank.

[0086] In the embodiment, the deep water membrane treatment system output end is connected with the intermediate water tank input end, forming a water production circulation system.

[0087] The water produced by the deep water treatment module is directly pumped to the intermediate water tank, mixed with the first RO produced water of the desalted water treatment module, and the indexes are better than the first RO produced water as shown in Table 2; the production water usage is reduced, and the first RO system processing cost is reduced.

[0088] Table 2

[0089]

[0090] In this embodiment, in order to avoid other unpredictable problems, the initial water supply is 200m 3 Water supply, observe the desalted water index fluctuation of the desalted water module, observe the user water quality fluctuation, and gradually increase the supply after stabilization, and the daily average water supply of 1000m 3 .

[0091] Preferably, a pH and turbidity online monitor is arranged between the mechanical stirring clarifier and the deep water membrane treatment system.

[0092] In this embodiment, the water produced after the mechanical stirring clarifier is sent for inspection every two hours, and the hardness and conductivity are detected to ensure the pretreated water quality monitoring.

[0093] By arranging the pH and turbidity online monitor, the qualified water enters the deep water membrane treatment system, and the unqualified water returns to the deep water conditioning tank, so that the water quality of the final produced water is as shown in Table 3, and the indexes of the deep water produced water are continuously stable.

[0094] Table 3

[0095] name PH Conductivity (µs / cm) Hardness umol / L Qualified effluent 7--9 <3000 <1500

[0096] As Figure 2 shown, the mechanical stirring clarifier includes a tank body 1, a water inlet pipe 11, a water outlet pipe 5, a cover body 6, a fixing frame 4, a hollow cylinder 7, a sludge concentration chamber 9, a motor 2, and a plurality of dosing pipes 17; wherein

[0097] The motor 2 is fixed at the top end of the tank body 1, and the motor 2 is fixedly connected with a stirring shaft 3 at the bottom end. The stirring shaft 3 penetrates through the top end of the tank body 1, and the fixing frame 4, the stirrer 15 and the mud scraping plate 8 are fixed on the stirring shaft 3 from top to bottom. The bottom end of the fixing frame 4 is fixedly connected with the top end of the cover body 6. The hollow cylinder 7 is fixedly connected with the stirring shaft 3 and located inside the cover body 6. The top end and the bottom end of the hollow cylinder 7 are provided with openings. The stirrer 15 is located inside the hollow cylinder 7. The mud scraping plate 8 is located below the cover body 6. A plurality of water collecting grooves 14 are arranged on the fixing frame 4.

[0098] The water inlet pipe 11 penetrates through the side wall of the tank body 1 and communicates with the inside of the hollow cylinder 7. The water outlet pipe 5 penetrates through the side wall of the tank body 1 and communicates with the water collecting groove 14.

[0099] The sludge concentration chamber 9 is fixed at the bottom end of the pool body 1 and is located below the mud scraping plate 8, and the sludge concentration chamber 9 is connected with the sewage pipe 10 to communicate with the outside world.

[0100] The plurality of dosing pipes 17 are fixedly connected with the top end of the pool body 1.

[0101] In the embodiment, the inside of the hollow cylinder 7 is the first reaction chamber 16, the inside of the cover body 6 is the second reaction chamber 12, and the outside of the cover body is the separation chamber 13.

[0102] In the embodiment, the plurality of dosing pipes 17 respectively communicate with the first reaction chamber 16, the second reaction chamber 12 and the separation chamber 13.

[0103] By using the above technical scheme, the mechanical stirring clarifier is used to treat water, and the solid-liquid separation effect is improved, and the water quality of the produced water is improved.

[0104] In the embodiment, the rotating speed of the motor 2 in the mechanical stirring clarifier is 400-800 r / min.

[0105] By using the above technical scheme, the rotating speed of the stirrer is controlled according to the size of the water inflow, and the stability of operation is improved.

[0106] In the embodiment, the working principle of the mechanical stirring clarifier is as follows: raw water enters the first reaction chamber 16 through the water inlet pipe 11, and in the first reaction chamber 16, the water and a large amount of backflow sludge are uniformly mixed due to the addition of reagents and the stirring of the upper blades of the stirrer 15, and are lifted to the second reaction chamber 12, and a process of adding reagents and flocculation growth is carried out here; the water flows into the separation chamber 13 through the second reaction chamber 12; in the separation chamber 13, the water flow speed is slowed down, and the sludge and the water are separated by adding reagents, and the separated water flows into the water collecting tank 14; the sludge separated from the separation chamber 13 is mostly backflowed to the first reaction chamber 16, and part of it enters the sludge concentration chamber 9; the sludge entering the first reaction chamber 16 flows with the water inflow; the sludge entering the sludge concentration chamber 9 is periodically discharged, and the sewage pipe 10 is arranged at the bottom of the clarifier for sludge discharge.

[0107] In the embodiment, the micro-vortex clarifier includes a pool body two, a water inlet pipe 20, a hollow cylinder two 19, a baffle bin 22, a floating ball stirrer 18 and a sludge discharge pipe 21, the hollow cylinder two 19 and the baffle bin 22 are arranged inside the pool body two, the water inlet pipe 20 penetrates through the side wall of the pool body two and communicates with the hollow cylinder two 19, the baffle bin 22 is located outside the hollow cylinder two 19, an inclined plate filter is arranged at the top of the baffle bin 22, a plurality of sludge discharge pipes 21 are arranged at the bottom of the baffle bin 22, the sludge discharge pipes 21 communicate with the outside world, and a water outlet pipe penetrates through the side wall of the pool body two and communicates with the baffle bin 22.

[0108] Specific working process: the micro-vortex clarifier tank is added with micro-vortex special phosphorus-free water treatment scale inhibitor, dispersant and bactericide, the treated water enters the center tube 2 19 through the water inlet pipeline 20, mixes with the medicament, is stirred by the floating ball stirrer 18, enters the baffle bin 22, and then the precipitated sludge is accelerated by the inclined plate filter and discharged to the deep water treatment station pressure filter through the sludge discharge pipeline 21, and the supernatant enters the water outlet pipeline to the clarified water tank.

[0109] In specific embodiments:

[0110] Raw water tank: volume: 200 m 3 , specification: φ6560 mm, number: 1, structure: polyurea lining;

[0111] Primary RO system: water production: 75 m 3 / h, recovery rate: 75%, arrangement mode: 9x6:4x6, number: 4 sets, model: BW30-400, material: aromatic polyamide, membrane area: 400 ft 2 , desalination rate: ≥99.6%, single element maximum pressure loss: 10 Psi, number: 78, arrangement mode: 10:5;

[0112] Intermediate water tank: volume: 50 m 3 , specification: φ6560 mm, number: 2, structure: steel polyurea corrosion protection;

[0113] Secondary RO system: water production: 60 m 3 / h, recovery rate: 80%, arrangement mode: 5x6:4x6, number: 4 sets, model: BW30-400, material: aromatic polyamide, membrane area: 400 ft 2 , desalination rate: ≥99.6%, single element maximum pressure loss: 10 Psi, number: 54;

[0114] Micro-vortex clarifier tank: volume: 50 m 3 , specification: φ6560 mm, number: 1, structure: concrete;

[0115] Clarified water tank: volume: 50 m 3 , number: 21, structure: steel polyurea corrosion protection;

[0116] Deep water conditioning tank: volume: 1000 m 3 (divided into two sections, each section is 500 m 3 ), number: 1, concrete structure;

[0117] Mechanical stirring tank: number: 1, output: 170 m 3 / h, body material: steel polyurea corrosion protection, volume: 42.5 m 3Diameter: φ4000 mm, Height (straight tube height): 3250 mm

[0118] Mechanical stirring clarifier: Number: 1, Output: 170 m 3 / h, Body material: steel polyurea corrosion prevention, Diameter: φ9000 mm, Height (straight tube height): 5950 mm, First reaction chamber diameter: φ1350 mm, Second reaction chamber diameter: φ4500 mm, Mud scraper power: 0.8 KW;

[0119] The deep water film treatment system comprises, which are connected in sequence, an ultrafiltration device, a raw water reverse osmosis device, and a concentrated water reverse osmosis device.

[0120] The ultrafiltration device has a model number of AQFHP-SXL55, a number of 2 sets, 24 membrane sets per set, a water production output of 70 m 3 / h, Recovery rate: 93%, Flux: ≤55 LMH, Membrane area: 55 m 2 ;

[0121] The raw water reverse osmosis device has a model number of BW30-365FR, a number of 2 sets, 72 membrane sets per set, and a water production output of 49 m 3 / h, Recovery rate: 70%, Flux: ≤20.07 LMH, Membrane area: 34 m 2 ;

[0122] The concentrated water reverse osmosis device has a model number of SW30ULE-400i, a number of 2 sets, 30 membrane sets per set, and a water production output of 13 m 3 / h, Recovery rate: 60%, Flux: ≤11.3 LMH, Membrane area: 37 m 2 .

[0123] Production tank: Volume: 4000 m 3 , Number: 3, Concrete structure

[0124] Equipment cooling circulating water tank: Volume: 100 m 3 , Number: 1, Concrete structure

[0125] Cooling water system: Volume: 200 m 3 , Number: 1, Concrete structure

[0126] Hot water tank: Volume: 80 m 3 , Number: 1, Concrete structure

[0127] In this embodiment, if the control is improper, the alunite in the mechanical stirring clarifier pool floats into the clear water tank in large quantities, the water treatment effect of the mechanical stirring clarifier pool is reduced, the effluent water quality exceeds the standard, and the normal operation of the mechanical stirring clarifier pool is seriously affected. If the method of flushing the mechanical stirring clarifier pool is used, it is effective at the moment, but soon the alunite will run again. A large amount of flushing not only increases the water consumption and power consumption, but also increases the load of other operation acceleration pools in the case of ensuring the water supply, so that the alunite running is more obvious, and the alunite running phenomenon cannot be fundamentally and effectively solved. Therefore, the following points must be done well:

[0128] (1) Control the stirring machine speed in a reasonable range, which must be flexibly adjusted according to different water quality

[0129] The water inlet of the mechanical stirring acceleration clarifier pool comes from the outlet of the soda reaction tank. Generally, the turbidity does not change much, so controlling the stirring machine speed according to the size of the water inlet is an important measure for stable operation. The stirring machine speed is determined by the lifting flow of the stirring machine, which is 3-5 times the water inlet. The stirring machine motor speed of the mechanical stirring clarifier pool is controlled at 400-800 r / min, and the stirring machine paddle rotation speed has three types of stepless speed regulation, multiple speed and constant speed. Among them, the stepless speed regulation can be adjusted according to the changes of raw water turbidity, water quantity, pH, temperature and dosage of coagulant to achieve ideal treatment effect. The commonly used mechanical stirring clarifier pool stirring machine has impeller and pump wheel integrated type and separate speed regulation type. When the water inlet is large, the speed is high, and when the water inlet is small, the speed is low.

[0130] (2) Scientifically and reasonably add coagulant

[0131] The dosage of the mechanical stirring clarifier pool is related to the water inlet, water turbidity, and sludge concentration in the second reaction chamber. Scientifically and reasonably adding coagulant according to the changes of the above three is the key to stable operation of the acceleration pool. If the water turbidity is low, in order to form the required sludge concentration, the water inlet can be reduced and the dosage can be increased. If necessary, a coagulant aid or loess can be added to the second reaction chamber. When the water quantity needs to be increased or decreased in the acceleration pool, the dosage of the coagulant should be adjusted in advance, and then the water quantity should be adjusted according to the requirements. When the sludge sedimentation ratio in the second reaction chamber decreases, the dosage of the coagulant should be increased immediately. At the same time, considering the problem of operation cost, the original pretreatment hardness removal method of sodium hydroxide + soda is adjusted to lime milk + soda hardness removal method, the coagulant is adjusted to polymeric ferric sulfate, and the dosing point is changed from the inlet of the mechanical stirring pool to the soda reaction tank, so that the coagulant can be fully mixed with the water inlet, and the phenomenon of uneven sedimentation effect in the mechanical stirring pool can be avoided.

[0132] (3) Reasonably arrange the sludge discharge

[0133] The mechanical stirring clarifier reasonably discharges sludge, so that the sludge maintains a certain concentration and activity, and the adsorption capacity of the sludge is maintained, so that the effluent quality of the acceleration tank is qualified. When the settling ratio of the sludge in the second reaction chamber of the acceleration tank is 15%, the acceleration tank can discharge sludge, so that the settling ratio of the sludge in the second reaction chamber of the acceleration tank is maintained within 10-15%. By monitoring the settling ratio of the sludge in the second reaction chamber, it is determined whether to discharge sludge, so as to prevent under-discharge and over-discharge. At the same time, in order to ensure the smoothness of the backflow port, the bottom sludge and underwater equipment are checked every quarter, and the acceleration tank is emptied and checked once every quarter.

[0134] (Four) Other measures

[0135] Before the raw water enters the mechanical stirring clarifier, the coagulant aid is added in the soda reaction tank to eliminate the influence of part of algae and improve the coagulation effect. The water quantity adjustment should be gradual, and the sudden increase of the water quantity should be avoided, especially when the water temperature difference is large. The water quantity should be gradually increased in small amounts to prevent water disturbance and even pool overturning. The acceleration tank structure is transformed to reduce the structure window, so as to avoid the sunlight bias and cause the local water convection of the acceleration tank, resulting in the loss of alum flowers.

[0136] Second, strengthen the maintenance and management of membrane treatment equipment, mainly chemical cleaning.

[0137] Due to the poor quality of the primary concentrated water and production water, the pretreatment capacity is not perfect in the early stage, which leads to the poor water quality of the membrane treatment system. Long-time operation causes a certain degree of fouling and blockage of the ultrafiltration and reverse osmosis equipment in the depth water regulation tank, which affects the water quantity and quality. Through the analysis and experiment of the internal fouling of the membrane, according to the special situation of high iron content and high COD content in the water quality, it is determined to continuously use NP216 high-iron scale inhibitor. Therefore, a new chemical cleaning method is adopted. Sodium hydroxide, EDTA4Na salt, hydrochloric acid, citric acid, sodium bisulfite and sodium dodecyl benzene sulfonate are selected. According to the fouling situation of the reverse osmosis membrane each time, the pH of the solution is adjusted to about 10-11 alkaline cleaning solution, and the pH of the solution is adjusted to about 1-3 according to the fouling situation of the reverse osmosis membrane each time.

[0138] The multi-stage reuse system of industrial wastewater (primary concentrated water) has many advantages such as not affected by weather, not competing for water with adjacent areas, local availability, stability and reliability, and high guarantee rate. Different treatment can achieve different reuse standards, which can effectively save clean water resources and reduce water environmental pollution. Following the idea of circular economy and the principle of water resource conservation and water environment friendly, the principle of "reduction, reuse and recycling" is always followed in the process of water resource application, the utilization efficiency and benefit of water are improved, and the pollution is minimized.

[0139] The project of improving water recycling rate solves the problems of protecting water resources, improving water recycling efficiency, saving water resources, establishing a virtuous cycle of water resources and protecting the surrounding environment by combining scientific planning, scientific progress and scientific mechanism.

[0140] The industrial wastewater multi-stage recycling system designed according to the application has the following technical effects:

[0141] (1) The primary thick water recycling system embodies the unity of comprehensiveness, completeness and practicability as a whole, and the water treatment technology is closely combined with reasonable recycling, breaking the original water treatment process. According to the characteristics and current situation of the water resources in the factory area, a water resource recycling system is gradually formed, so that the primary thick water can be recycled in multiple stages according to demand, quality and flow, improving the efficiency of water resource recycling. The primary thick water resource is the main line, and the treatment method combining industrialized treatment and ecological purification is integrated. The combination of water resource regeneration and water area ecological environment restoration is beneficial to promoting the improvement of water environment, and effectively forms a large-scale water resource recycling system.

[0142] (2) The primary thick water is used as a supplement to comprehensively develop various new water sources and their multiple recycling ways at different levels, basically forming a closed-loop recycling of regenerated water, greatly improving the regional water resource recycling rate. The primary thick water resource is the main line, and the treatment method combining industrialized treatment and ecological purification is integrated. The combination of water resource regeneration and water area ecological environment restoration is beneficial to promoting the improvement of water environment;

[0143] (3) The scientific system of water resource recycling is constructed, and the production and application of regenerated water are diversified, so that the primary thick water recycling becomes an important support for regional water resources.

[0144] (4) After the implementation of the project of improving water recycling rate, the treatment capacity of the deep water membrane treatment section is effectively improved, and the water production index is improved, which is much better than the primary water production index of the desalted water treatment module. The deep water is directly supplied to the intermediate water tank of the desalted water treatment module. For the desalted water module, since the deep water is directly supplied to the chemical water intermediate water tank, the use amount of new water of the desalted water module is greatly reduced, the primary thick water discharge amount is reduced, the start-up time of the chemical water pretreatment system and the primary reverse osmosis is reduced, and a large amount of cost is saved.

[0145] The parts not described in detail in the embodiments of the application can be realized by using the prior art, and are not described here.

[0146] The various embodiments described in this specification are presented by way of example, and each embodiment is not necessarily composed of all features described with respect to other embodiments. Each embodiment describes a distinct aspect of the present application, and each aspect can be used in combination with one or more other aspects.

[0147] The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-stage industrial wastewater reuse system, characterized in that, The application relates to a water treatment system. The system comprises a desalted water treatment module, a deep water treatment module and a cooling water treatment module which are connected with each other. The desalted water treatment module comprises a raw water tank, a first RO system, an intermediate water tank, a second RO system, a micro-vortex clarifier and a clarified water tank. The output end of the raw water tank is connected with the input end of the first RO system, the intermediate water tank and the second RO system in sequence. The output end of the first RO system is connected with the input end of the micro-vortex clarifier. The output end of the second RO system is connected with the input end of the raw water tank, forming a first water supplementing circulation system. The deep water treatment module comprises a deep water adjusting tank, a deep water stirring tank, a mechanical stirring clarifier, a deep water membrane treatment system and a production water tank. The output end of the micro-vortex clarifier and the output end of the first RO system are connected with the input end of the deep water adjusting tank. The output end of the deep water adjusting tank is connected with the input end of the deep water stirring tank, the mechanical stirring clarifier, the deep water membrane treatment system and the production water tank in sequence. The output end of the production water tank is connected with the input end of other users. The output end of the production water tank is connected with the input end of the raw water tank, forming a second water supplementing circulation system. The output end of the mechanical stirring clarifier is connected with the input end of the deep water adjusting tank. The output end of the deep water membrane treatment system and an external water source are connected with the input end of the production water tank. The output end of the deep water membrane treatment system is connected with the input end of the intermediate water tank, forming a production water circulation system. The cooling water treatment module comprises a device cooling circulating water tank, a cooling water system and a hot water tank. The output end of the micro-vortex clarifier is connected with the input end of the clarified water tank, the device cooling circulating water tank, the cooling water system, the hot water tank and the micro-vortex clarifier in sequence. The output end of the production water tank is connected with the input end of the device cooling circulating water tank. The output end of the cooling water system is connected with the input end of the deep water adjusting tank. The micro-vortex clarifier comprises a tank body two, a water inlet pipeline (20), a hollow cylinder two (19), a baffle bin (22), a floating ball agitator (18) and a sludge discharge pipeline (21), the tank body two is internally provided with the hollow cylinder two (19) and the baffle bin (22), the water inlet pipeline (20) penetrates through the side wall of the tank body two and communicates with the hollow cylinder two (19), the baffle bin (22) is located outside the hollow cylinder two (19), an inclined plate filter is arranged at the top of the baffle bin (22), and a plurality of sludge discharge pipelines (21) are arranged at the bottom of the baffle bin (22), the sludge discharge pipelines (21) communicate with the outside, and a water outlet pipeline penetrates through the side wall of the tank body two and communicates with the baffle bin (22). The micro-vortex clarifier is provided with a micro-vortex special phosphorus-free water treatment scale inhibitor, a dispersant and a bactericide, treated water enters the center cylinder two (19) through the water inlet pipeline (20) and mixes with the medicaments, is stirred by the floating ball agitator (18) and then enters the baffle bin (22), and the sludge is accelerated to precipitate through the inclined plate filter, is discharged to a deep water treatment station filter press through the sludge discharge pipeline (21), and the supernatant enters the water outlet pipeline and then enters the clarified water tank.

2. The multi-stage industrial wastewater reuse system of claim 1, wherein, The mechanical stirring clarifying tank is provided with pH and turbidity on-line monitoring instruments between the mechanical stirring clarifying tank and the deep water film treatment system.

3. The multi-stage industrial wastewater reuse system of claim 1, wherein The mechanical stirring clarifying tank comprises a tank body (1), a water inlet pipe (11), a water outlet pipe (5), a cover body (6), a fixing frame (4), a hollow cylinder (7), a sludge concentration chamber (9), a motor (2) and a plurality of dosing pipes (17); wherein The motor (2) is fixed at the top end of the tank body (1), and the motor (2) is fixedly connected with a stirring shaft (3) at the bottom end; the stirring shaft (3) penetrates through the top end of the tank body (1), and a fixing frame (4), a stirrer (15) and a mud scraping plate (8) are fixed on the stirring shaft (3) from top to bottom; the bottom end of the fixing frame (4) is fixedly connected with the top end of the cover body (6); the hollow cylinder (7) is fixedly connected with the stirring shaft (3) and located inside the cover body (6); the top end and the bottom end of the hollow cylinder (7) are provided with openings; the stirrer (15) is located inside the hollow cylinder (7); the mud scraping plate (8) is located below the cover body (6); and a plurality of water collecting grooves (14) are arranged on the fixing frame (4). The water inlet pipe (11) penetrates through the side wall of the tank body (1) and is in communication with the inside of the hollow cylinder (7); and the water outlet pipe (5) penetrates through the side wall of the tank body (1) and is in communication with the water collecting grooves (14). The sludge concentration chamber (9) is fixed at the bottom end of the tank body (1) and located below the mud scraping plate (8); and the sludge concentration chamber (9) is connected with a blowdown pipe (10) to communicate with the outside. The plurality of dosing pipes (17) are fixedly connected with the top end of the tank body (1).

4. The multi-stage industrial wastewater reuse system of claim 3, wherein, The inside of the hollow cylinder (7) is a first reaction chamber (16), the inside of the cover body (6) is a second reaction chamber (12), and the outside of the cover body is a separation chamber (13).

5. The multi-stage industrial wastewater reuse system of claim 4, wherein, The plurality of dosing pipes (17) are respectively in communication with the first reaction chamber (16), the second reaction chamber (12) and the separation chamber (13).

6. The multi-stage industrial wastewater reuse system of claim 3, wherein, The rotating speed of the stirring shaft (3) is 400-800 r / min.

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