A system for comprehensive treatment and reuse of rainwater and production wastewater in a metallurgical plant

Abstract

The utility model discloses a kind of comprehensive treatment and reuse system of metallurgical plant area rainwater and production wastewater, belong to water treatment field.The system includes parallelly arranged rainwater standard treatment system and production wastewater pretreatment system;Rainwater standard treatment system and production wastewater pretreatment system include sequentially connected first-stage reaction sedimentation tank, second-stage reaction sedimentation tank, third-stage reaction sedimentation tank, integrated aeration filter tank;Production wastewater pretreatment system after processing wastewater and / or rainwater standard treatment system after processing rainwater enter multi-medium filter, ultrafiltration device, after multi-medium filtration and ultrafiltration, into ultrafiltration water tank, the water in ultrafiltration water tank is treated after reverse osmosis device, and water enters reverse osmosis water tank storage, and then add liquid caustic soda recycling.The utility model has the advantages of simple operation, high degree of automation, flexible operation, stable and reliable, good treatment effect etc., is a complete rainwater and production wastewater comprehensive treatment and reuse system with wastewater zero discharge function.

Description

Technical Field

[0001] This utility model belongs to the field of water treatment technology, specifically relating to the field of rainwater and industrial wastewater treatment in the metallurgical industry, and particularly to a comprehensive treatment and reuse system for rainwater and industrial wastewater in metallurgical plants. Background Technology

[0002] The metallurgical industry generates large volumes of wastewater, primarily from drainage of circulating cooling water systems, slag flushing wastewater, and wastewater condensed, separated, or overflowing from production processes. This wastewater is characterized by its diverse types, complex and variable quality, high content of heavy metals such as arsenic, lead, cadmium, and thallium, high hardness, and high salinity. Furthermore, rainwater runoff within the plant area inevitably introduces some heavy metal pollutants into the collected rainwater, especially in the initial rainwater runoff, where pollutant levels often exceed standards. Heavy metals are the main pollutants in both wastewater and rainwater from smelting enterprises. Direct discharge into the environment without treatment would cause significant damage. Therefore, collecting rainwater and wastewater from metallurgical plants and exploring a comprehensive treatment system and method to reduce heavy metal ion content, mitigate environmental pollution, and improve water recycling rates has practical value. Summary of the Invention

[0003] The purpose of this invention is to provide a new solution for the treatment of rainwater and industrial wastewater in metallurgical plants. It proposes a comprehensive treatment and reuse system for rainwater and industrial wastewater in metallurgical plants that has strong comprehensive treatment capacity, simple operation, high degree of automation, flexible operation, stability and reliability, good treatment effect, and achieves zero discharge.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A comprehensive treatment and reuse system for rainwater and industrial wastewater in a metallurgical plant area includes a rainwater treatment system and an industrial wastewater pretreatment system arranged in parallel, as well as a multi-media filter, an ultrafiltration unit, an ultrafiltration product water tank, a reverse osmosis unit, a reverse osmosis product water tank, and a reverse osmosis concentrate tank; wherein, The rainwater treatment system includes a primary rainwater reaction sedimentation tank, a secondary rainwater reaction sedimentation tank, a tertiary rainwater reaction sedimentation tank, and an integrated rainwater aeration and filtration tank connected in sequence. The production wastewater pretreatment system includes a primary reaction sedimentation tank, a secondary reaction sedimentation tank, a tertiary reaction sedimentation tank, and an integrated aeration and filtration tank for production wastewater, connected in sequence. Wastewater treated by the production wastewater pretreatment system and / or rainwater treated by the rainwater treatment system enter a multi-media filter and an ultrafiltration device. After multi-media filtration and ultrafiltration, the water enters the ultrafiltration product water tank. The product water in the ultrafiltration product water tank is treated by the reverse osmosis device and then enters the reverse osmosis product water tank for storage. Liquid alkali is then added for recycling. After treatment by the reverse osmosis unit, part of the concentrate flows into the reverse osmosis concentrate tank, and part flows back to the ultrafiltration permeate tank, where it is then treated by the reverse osmosis unit before flowing into the reverse osmosis concentrate tank.

[0005] Furthermore, the rainwater primary reaction sedimentation tank, rainwater secondary reaction sedimentation tank, rainwater tertiary reaction sedimentation tank, production wastewater primary reaction sedimentation tank, production wastewater secondary reaction sedimentation tank, and production wastewater tertiary reaction sedimentation tank are all integrated equipment consisting of four chemical dosing reaction tanks connected in series and an inclined plate sedimentation tank.

[0006] Furthermore, the dosing reaction tank is a coagulation sedimentation tank.

[0007] Furthermore, the inclined plate sedimentation tank employs three different separation methods: co-current flow, counter-current flow, and lateral flow.

[0008] Furthermore, soda ash, liquid alkali, thallium removal agent, and PAM are sequentially added to the four-compartment chemical dosing tank connected in series in the rainwater primary reaction sedimentation tank and the production wastewater primary reaction sedimentation tank.

[0009] Furthermore, liquid alkali, biological agent, PAC, and PAM are sequentially added to the four-compartment chemical dosing tank connected in series in the rainwater secondary reaction sedimentation tank and the production wastewater secondary reaction sedimentation tank.

[0010] Furthermore, in the four-compartment chemical dosing tank of the rainwater three-stage reaction sedimentation tank and the production wastewater three-stage reaction sedimentation tank connected in series, liquid alkali, biological agent and PAM are added in sequence, and no agent is added in the fourth compartment.

[0011] Furthermore, both the integrated rainwater aeration and filtration tank and the integrated wastewater aeration and filtration tank are integrated devices composed of an aeration oxidation tank, a sand filter tank, and an intermediate water tank connected in sequence.

[0012] Furthermore, compressed air is introduced into the aerated oxidation tank for aeration, and microporous aerators are installed at the bottom of the tank, with a maximum service area of ​​1m². 2 .

[0013] Furthermore, the sand filter tank is filled with quartz sand filter media, including two specifications: 0.5-1.2mm in particle size and 1-2mm in particle size, with a volume ratio of 7:3.

[0014] Furthermore, the multi-media filter adopts a double-layer filtration method, with the upper layer filled with anthracite coal with a particle size of 1.2-2.5mm and the lower layer filled with quartz sand with a particle size of 0.5-1.2mm. The volume ratio of anthracite coal to quartz sand is 1:2.

[0015] Furthermore, the ultrafiltration membrane in the ultrafiltration device is an externally pressurized PVDF hollow fiber membrane with a filtration flux of 40-60 L / m³. 2 ·h.

[0016] Furthermore, the reverse osmosis device adopts a one-stage two-stage process, and the reverse osmosis membrane is selected from DuPont anti-fouling brackish water reverse osmosis membrane elements. The device has a recovery rate of 70% and a desalination rate of over 97%.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. This utility model provides a comprehensive treatment system for rainwater and production wastewater in a metallurgical plant area. The rainwater treatment system and the production wastewater pretreatment system are set up in parallel. The two treatment systems have the same function, can operate independently or serve as backups for each other, and have a high degree of automation and flexible operation.

[0018] 2. This utility model system is a complete integrated treatment and reuse system for rainwater and industrial wastewater with zero wastewater discharge capability. Rainwater treatment effluent is pumped into a rainwater production tank for later use; industrial wastewater, after membrane treatment, is pumped to a softened water reuse point, while the concentrate is reused at low-quality water usage points such as slag flushing and battery dismantling. Wastewater from sand filter backwashing and membrane system processes is returned to the primary reaction sedimentation tank for further treatment. The entire system has no other additional wastewater discharge. The system has a high recycling rate and reduces its impact on the surrounding environment. Attached Figure Description

[0019] Figure 1 This is a system structure diagram of the present invention; Figure 2 This is a structural diagram of a primary sedimentation tank for rainwater. Figure 3 This is a structural diagram of an integrated rainwater aeration and filtration tank. In the diagram: 1-Rainwater primary reaction sedimentation tank, 2-Rainwater secondary reaction sedimentation tank, 3-Rainwater tertiary reaction sedimentation tank, 4-Rainwater integrated aeration and filtration tank, 1'-Production wastewater primary reaction sedimentation tank, 2'-Production wastewater secondary reaction sedimentation tank, 3'-Production wastewater tertiary reaction sedimentation tank, 4'-Production wastewater integrated aeration and filtration tank, 5-Rainwater product water tank, 6-Multi-media filter, 7-Ultrafiltration device, 8-Ultrafiltration product water tank, 9-Reverse osmosis device, 10-Reverse osmosis product water tank, 11-Reverse osmosis concentrate tank. Detailed Implementation

[0020] The technical solution and effects of this utility model will be further described below with reference to the accompanying drawings and specific embodiments, but the protection scope of this utility model is not limited thereto. Example 1

[0021] like Figure 1As shown, this embodiment provides a comprehensive treatment and reuse system for rainwater and industrial wastewater in a metallurgical plant, including a rainwater treatment system and an industrial wastewater pretreatment system arranged in parallel, as well as a multi-media filter 6, an ultrafiltration device 7, an ultrafiltration product water tank 8, a reverse osmosis device 9, a reverse osmosis product water tank 10, and a reverse osmosis concentrate tank 11; wherein, The rainwater treatment system includes a primary rainwater reaction sedimentation tank 1, a secondary rainwater reaction sedimentation tank 2, a tertiary rainwater reaction sedimentation tank 3, and an integrated rainwater aeration and filtration tank 4, which are connected in sequence. The rainwater that meets the standards after being treated by the rainwater treatment system is partly stored in the rainwater production tank 5 as production water, and partly enters the multi-media filter for further treatment.

[0022] The production wastewater pretreatment system includes a primary reaction sedimentation tank 1', a secondary reaction sedimentation tank 2', a tertiary reaction sedimentation tank 3', and an integrated aeration and filtration tank 4' connected in sequence. Wastewater treated by the production wastewater pretreatment system and / or rainwater treated by the rainwater compliant treatment system enter the multi-media filter 6 and the ultrafiltration device 7. After multi-media filtration and ultrafiltration, the water enters the ultrafiltration product water tank 8. The product water in the ultrafiltration product water tank 8 is treated by the reverse osmosis device 9 and then enters the reverse osmosis product water tank 10 for storage. Liquid alkali is then added for recycling. Part of the concentrate after treatment by the reverse osmosis unit 9 flows into the reverse osmosis concentrate tank 11, and part flows back to the ultrafiltration permeate tank 8, and then flows into the reverse osmosis concentrate tank 11 after being treated by the reverse osmosis unit 9 again.

[0023] In this embodiment, the rainwater treatment system and the wastewater pretreatment system in the integrated treatment and reuse system for rainwater and production wastewater in the metallurgical plant area have the same function. They can operate independently or serve as backups for each other, and are highly automated and flexible in operation.

[0024] As a specific implementation method, the rainwater primary reaction sedimentation tank 1, rainwater secondary reaction sedimentation tank 2, rainwater tertiary reaction sedimentation tank 3, and industrial wastewater primary reaction sedimentation tank 1', industrial wastewater secondary reaction sedimentation tank 2', and industrial wastewater tertiary reaction sedimentation tank 3' are all integrated devices composed of four chemical dosing reaction tanks connected in series and an inclined plate sedimentation tank. Taking the rainwater primary reaction sedimentation tank 1 as an example, its structure is shown in […]. Figure 2 .

[0025] In this embodiment, the sludge produced by the sedimentation of the primary rainwater reaction sedimentation tank 1, the secondary rainwater reaction sedimentation tank 2, the tertiary rainwater reaction sedimentation tank 3, the primary wastewater reaction sedimentation tank 1', the secondary wastewater reaction sedimentation tank 2', and the tertiary wastewater reaction sedimentation tank 3' enters the sludge thickening tank for storage and is used as auxiliary material for furnaces and kilns.

[0026] The chemical dosing reaction tank of this invention adopts a coagulation sedimentation tank commonly used in the art. In the inclined plate sedimentation tank, there is a very shallow sedimentation pool between every two parallel inclined plates, allowing the treated water (or wastewater) and the settled sludge to move and separate in the shallow sedimentation layer. Based on the force direction of their mutual movement, three different separation methods can be distinguished: co-current flow, counter-current flow, and lateral flow. This embodiment adopts the counter-current flow separation method. The inclined plate sedimentation tank utilizes the principle of "shallow sedimentation," shortening the particle settling distance, thereby shortening the sedimentation time and increasing the sedimentation area of ​​the sedimentation pool, thus improving treatment efficiency. The inclined plate sedimentation tank of this invention is an existing structure in the art, and its specific structure will not be described in detail here.

[0027] In this embodiment, when the system is working, liquid alkali is added to the first compartment of the rainwater primary reaction sedimentation tank 1 and the production wastewater primary reaction sedimentation tank 1' to adjust the pH value of the wastewater to 9-10, and soda ash is added to cause calcium and magnesium ions in the water to precipitate and be removed, thereby reducing hardness; thallium removal agent is added to the second compartment to remove thallium; PAM is added to the third compartment to coagulate fine particles into large particles, which are then separated by sedimentation; no reagent is added to the fourth compartment, which serves to buffer and prolong the reaction time.

[0028] When the system is working, liquid alkali is added to the first compartment of the rainwater secondary reaction sedimentation tank 2 and the production wastewater secondary reaction sedimentation tank 2' to adjust the pH value of the wastewater to 9~10; biological agents are added to the second compartment to remove heavy metals and PAC is added for coagulation; PAM is added to the third compartment to aid coagulation; no agents are added to the fourth compartment, which serves to buffer and prolong the reaction time.

[0029] When the system is working, liquid alkali is added to the first compartment of the rainwater three-stage reaction sedimentation tank 3 and the production wastewater three-stage reaction sedimentation tank 3' to adjust the pH value of the wastewater to 9~10; biological agents are added again to the second compartment to further reduce heavy metals; PAM is added to the third compartment to aid coagulation; no agents are added to the fourth compartment, which plays a role in buffering and prolonging the reaction time.

[0030] The thallium removal agent used in this invention system can be iron salt, nano thallium removal agent, sodium sulfide, etc., all of which can react with thallium ions to generate stable precipitates to remove thallium ions.

[0031] The biological agents used in this invention system can be heavy metal ion adsorbents, CT-NM series heavy metal wastewater treatment agents, etc. When treating heavy metal wastewater, these biological agents can effectively adsorb, precipitate, or form complexes with heavy metal ions, thereby reducing the content of heavy metal ions in the water.

[0032] The dosage of each agent is as follows: (1) Prepare liquid alkali with a concentration of 30% to adjust the pH of the wastewater to 9-10; (2) Prepare soda ash with a concentration of 10% and the dosage is determined according to the hardness of the wastewater; (3) Prepare PAC with a concentration of 10% and the dosage is 20-30 mg / L; (4) Prepare PAM with a concentration of 0.3% and the dosage is 2-5 mg / L; (5) Add thallium removal agent according to the thallium content in the wastewater; (6) Add biological agent according to the heavy metal content in the wastewater.

[0033] As a specific implementation method, both the integrated rainwater aeration and filtration tank 4 and the integrated wastewater aeration and filtration tank 4' are integrated devices composed of an aeration oxidation tank, a sand filter, and an intermediate water tank connected in sequence. Taking the integrated rainwater aeration and filtration tank 4 as an example, its structure is shown below. Figure 3 .

[0034] In this embodiment, compressed air is introduced into the aeration oxidation tank for aeration, and microporous aerators are installed at the bottom of the tank, with a maximum service area of ​​1m². 2 The sand filter is filled with quartz sand filter media from bottom to top, including two specifications: 0.5-1.2mm particle size and 1-2mm particle size, with a volume ratio of 7:3. The sand filter requires regular backwashing. Short-handled filter caps are installed on the bottom plate of the filter media as water distributors, and perforated aeration pipes for backwashing are installed at the bottom of the tank.

[0035] Furthermore, the backwash wastewater from the sand filter in the integrated rainwater aeration and filtration tank 4 is collected and then re-enters the rainwater primary reaction sedimentation tank 1 for treatment; the backwash wastewater from the sand filter in the integrated production wastewater aeration and filtration tank 4' is collected and then enters the production wastewater primary reaction sedimentation tank 1' for treatment.

[0036] In this embodiment, the multi-media filter 6 adopts a double-layer filtration. The upper layer is filled with anthracite with a particle size of 1.2-2.5mm; the lower layer is filled with quartz sand with a particle size of 0.5-1.2mm. The volume ratio of anthracite to quartz sand is 1:2.

[0037] The ultrafiltration membrane in ultrafiltration unit 7 is an external pressure PVDF hollow fiber membrane with a filtration flux of 40-60 L / m³. 2 ·h。 .

[0038] The reverse osmosis unit 9 adopts a single-stage two-stage process. The reverse osmosis membrane uses DuPont anti-fouling brackish water reverse osmosis membrane elements from the United States. The unit has a recovery rate of 70% and a desalination rate of over 97%.

[0039] The working principle of this utility model is as follows: (1) Rainwater first enters the primary reaction sedimentation tank of rainwater via a rainwater lift pump. Liquid alkali is added to adjust the pH value and soda ash, thallium removal agent and PAM are added for treatment before entering the inclined plate sedimentation tank. The main purpose is to remove thallium in the water and reduce hardness. The effluent flows by gravity into the secondary reaction sedimentation tank of rainwater to adjust the pH and add biological agents, PAC and PAM to reduce the content of heavy metals such as lead and cadmium in the water. The effluent passes through the tertiary reaction sedimentation tank of rainwater. The pH is adjusted according to the water quality and biological agents and PAM are added to further reduce heavy metals. Then it enters the integrated aeration filter tank. The iron and manganese ions in the water are oxidized by aeration and then filtered and intercepted by the sand filter tank. At the same time, the turbidity of the effluent is further reduced. Part of the effluent is stored in the rainwater production tank 5 as production water and part enters the multi-media filter for further treatment.

[0040] (2) The production wastewater pretreatment system is similar to the rainwater treatment system. The production wastewater passes through the primary reaction sedimentation tank, the secondary reaction sedimentation tank, the tertiary reaction sedimentation tank, and the integrated aeration filter tank in sequence, and then is pumped into the multi-media filter of the membrane treatment system.

[0041] (3) The effluent from the multi-media filter is filtered by an ultrafiltration unit, and the permeate enters the ultrafiltration permeate tank. Then, it is pressurized by a high-pressure pump and passed through a reverse osmosis unit to separate salt and water. The reverse osmosis permeate is collected in the reverse osmosis permeate tank and pumped to the softened water reuse point. Liquid alkali is added at the pump outlet to adjust the pH, and a pH meter is installed. The concentrate is collected in the reverse osmosis concentrate tank and reused at low-quality water points such as sludge flushing and battery dismantling.

[0042] (4) The backwash wastewater from the sand filter in the rainwater treatment system is collected and then re-entered into the primary reaction sedimentation tank for rainwater treatment; the backwash wastewater from the sand filter in the production wastewater pretreatment system is collected and then entered into the primary reaction sedimentation tank for production wastewater treatment.

[0043] (5) The system is equipped with two sludge thickening tanks. The sludge from the integrated rainwater sedimentation tank is pumped into the inorganic sludge thickening tank, and the sludge from the integrated production wastewater sedimentation tank is pumped into the heavy metal sludge thickening tank. The supernatant from the inorganic sludge thickening tank is returned to the rainwater treatment system, and the supernatant from the heavy metal sludge thickening tank is returned to the production wastewater treatment system. The sludge from the thickening tanks is dewatered by a filter press and then disposed of as auxiliary material for furnaces and kilns. There is no other additional wastewater discharge from the system. Example 2

[0044] This embodiment uses rainwater and production wastewater from a non-ferrous metallurgical plant as the treatment targets, and adopts the system of Embodiment 1 to treat the rainwater and production wastewater.

[0045] Rainwater contained 2 mg / L lead, 1.8 mg / L arsenic, 1.5 mg / L cadmium, and 6 μg / L thallium. The production wastewater has a pH of 7-8, a conductivity of approximately 8000 μS / cm, suspended solids (SS) of approximately 150 mg / L, total hardness (calculated as calcium carbonate) of 2500 mg / L, lead of 3 mg / L, arsenic of 2.5 mg / L, cadmium of 2 mg / L, and thallium of 12 μg / L.

[0046] The specific processing steps are as follows: 1) Rainwater and industrial wastewater enter the rainwater treatment system and the industrial wastewater pretreatment system, respectively. In the first compartment of the primary sedimentation tank 1 for rainwater and the primary sedimentation tank 1' for industrial wastewater, liquid alkali is added to adjust the pH of the wastewater to 9-10, and soda ash is added to cause calcium and magnesium ions in the water to precipitate and be removed, thereby reducing hardness; in the second compartment, thallium removal agent is added to remove thallium; in the third compartment, PAM is added to coagulate fine particles into larger particles, which are then separated by sedimentation; no reagents are added to the fourth compartment, which serves to buffer and prolong the reaction time.

[0047] Liquid alkali is added to the first compartment of the secondary sedimentation tank 2 for rainwater and the secondary sedimentation tank 2' for production wastewater to adjust the pH value of the wastewater to 9-10; biological agents are added to the second compartment to remove heavy metals and PAC is added for coagulation; PAM is added to the third compartment to aid coagulation; no reagents are added to the fourth compartment, which serves to buffer and prolong the reaction time.

[0048] Liquid alkali is added to the first compartment of the three-stage reaction sedimentation tank 3 for rainwater and the three-stage reaction sedimentation tank 3' for production wastewater to adjust the pH value of the wastewater to 9-10; biological agents are added again to the second compartment to reduce heavy metals to an even lower level and ensure the removal rate; PAM is added to the third compartment to aid coagulation; no agents are added to the fourth compartment, which serves to buffer and prolong the reaction time.

[0049] The thallium removal agent used in this embodiment is an iron salt, which can react with thallium ions to form an insoluble iron salt precipitate to remove thallium ions.

[0050] The biological agent used in this embodiment is a heavy metal ion adsorbent. It can react rapidly with various heavy metal ions in wastewater at room temperature to generate water-insoluble high molecular weight chelate salts and form flocculent precipitates. After solid-liquid separation, the purpose of removing heavy metal ions is achieved.

[0051] The dosage of each agent is as follows: (1) Liquid alkali is prepared at a concentration of 30% and the pH value of the wastewater is adjusted to 9~10; (2) Soda ash is prepared at a concentration of 10% and the dosage for the rainwater system is 500mg / L and the dosage for the production wastewater system is 2650mg / L; (3) PAC is prepared at a concentration of 10% and the dosage is 20mg / L; (4) PAM is prepared at a concentration of 0.3% and the dosage is 2mg / L; (5) Thallium removal agent is prepared at a dosage of 25mg / L for the rainwater system and 50mg / L for the production wastewater system; (6) Biological agent is prepared at a dosage of 350mg / L for the rainwater system and 500mg / L for the production wastewater system.

[0052] After being treated by a three-stage reaction sedimentation tank and an integrated aeration filter, the rainwater and industrial wastewater have a suspended solids (SS) concentration of approximately 30 mg / L, a total hardness (calculated as calcium carbonate) of 250 mg / L, thallium < 0.5 μg / L, and other Class I pollutants meet the emission limits for production workshops or facilities in Table 1 of the "Emission Standard of Pollutants for Regenerated Copper, Aluminum, Lead and Zinc Industries" GB 31574-2015, namely lead ≤ 0.2 mg / L, arsenic ≤ 0.1 mg / L, and cadmium ≤ 0.01 mg / L.

[0053] 2) Of the rainwater that meets the standards after treatment by the rainwater treatment system, part is stored in rainwater production tank 5 as production water, and part enters a multi-media filter for further treatment. Wastewater treated by the production wastewater pretreatment system and rainwater treated by the rainwater treatment system enter the multi-media filter and ultrafiltration unit, and then enter the ultrafiltration product water tank. The product water in the ultrafiltration product water tank is treated by the reverse osmosis unit and then enters the reverse osmosis product water tank for storage. Liquid alkali is then added for reuse. After treatment by the reverse osmosis unit, part of the concentrate flows into the reverse osmosis concentrate tank, and part flows back to the ultrafiltration permeate tank, where it is treated again by the reverse osmosis unit to improve the system's permeate rate. The wastewater from the multi-media filter is filtered through an ultrafiltration unit, and the permeate enters the ultrafiltration permeate tank. It is then pressurized by a high-pressure pump and passed through a reverse osmosis unit to separate salts and water. The reverse osmosis permeate is collected in the reverse osmosis permeate tank and pumped to a softened water reuse point. Liquid alkali is added at the pump outlet to adjust the pH, and a pH meter is installed. The concentrate is collected in the reverse osmosis concentrate tank and reused at low-quality water usage points such as sludge flushing and battery dismantling.

[0054] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art 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 appended claims and their equivalents.

Claims

1. A comprehensive treatment and reuse system for rainwater and industrial wastewater in a metallurgical plant, characterized in that, The system includes a parallel rainwater treatment system and a production wastewater pretreatment system, as well as a multi-media filter (6), an ultrafiltration unit (7), an ultrafiltration product water tank (8), a reverse osmosis unit (9), a reverse osmosis product water tank (10), and a reverse osmosis concentrate tank (11); among which, The rainwater treatment system includes a primary rainwater reaction sedimentation tank (1), a secondary rainwater reaction sedimentation tank (2), a tertiary rainwater reaction sedimentation tank (3), and an integrated rainwater aeration and filtration tank (4), which are connected in sequence. The production wastewater pretreatment system includes a primary reaction sedimentation tank (1'), a secondary reaction sedimentation tank (2'), a tertiary reaction sedimentation tank (3'), and an integrated aeration and filtration tank (4') connected in sequence. Wastewater treated by the production wastewater pretreatment system and / or rainwater treated by the rainwater compliant treatment system enter the multi-media filter (6) and ultrafiltration device (7). After multi-media filtration and ultrafiltration, the water enters the ultrafiltration product water tank (8). The product water in the ultrafiltration product water tank (8) is treated by the reverse osmosis device (9) and then enters the reverse osmosis product water tank (10) for storage. Liquid alkali is then added for recycling. After being treated by the reverse osmosis unit (9), part of the concentrated water flows into the reverse osmosis concentrate tank (11), and part flows back to the ultrafiltration permeate tank (8), and after being treated by the reverse osmosis unit (9), it flows into the reverse osmosis concentrate tank (11).

2. The system according to claim 1, characterized in that, The rainwater primary reaction sedimentation tank (1), rainwater secondary reaction sedimentation tank (2), rainwater tertiary reaction sedimentation tank (3), production wastewater primary reaction sedimentation tank (1'), production wastewater secondary reaction sedimentation tank (2'), and production wastewater tertiary reaction sedimentation tank (3') are all integrated equipment consisting of four chemical dosing reaction tanks connected in series and an inclined plate sedimentation tank.

3. The system according to claim 2, characterized in that, The dosing reaction tank is a coagulation sedimentation tank, and the inclined plate sedimentation tank adopts three different separation methods: co-current flow, counter-current flow, and lateral flow.

4. The system according to claim 1, characterized in that, Soda ash, liquid alkali, thallium removal agent, and PAM are added sequentially to the four interconnected dosing tanks of the rainwater primary reaction sedimentation tank (1) and the production wastewater primary reaction sedimentation tank (1').

5. The system according to claim 1, characterized in that, Liquid alkali, biological agent, PAC, and PAM are sequentially added to the four-compartment dosing reaction tanks connected in series, including the rainwater secondary reaction sedimentation tank (2) and the production wastewater secondary reaction sedimentation tank (2').

6. The system according to claim 1, characterized in that, Liquid alkali, biological agent, and PAM are added sequentially to the four-compartment dosing reaction tanks of the rainwater three-stage reaction sedimentation tank (3) and the production wastewater three-stage reaction sedimentation tank (3'), while no agent is added to the fourth compartment.

7. The system according to claim 1, characterized in that, The integrated rainwater aeration and filtration tank (4) and the integrated production wastewater aeration and filtration tank (4') are both integrated equipment consisting of an aeration oxidation tank, a sand filter tank and an intermediate water tank connected in sequence. Compressed air is introduced into the aerated oxidation tank for aeration, and microporous aerators are installed at the bottom of the tank, with a maximum service area of ​​1m² per unit. 2 ; The sand filter tank is filled with quartz sand filter media from bottom to top, including two specifications: 0.5-1.2mm particle size and 1-2mm particle size, with a volume ratio of 7:

3.

8. The system according to claim 1, characterized in that, The multi-media filter (6) adopts a double-layer filtration. The upper layer is filled with anthracite with a particle size of 1.2-2.5 mm; the lower layer is filled with quartz sand with a particle size of 0.5-1.2 mm. The volume ratio of anthracite to quartz sand is 1:

2.

9. The system according to claim 1, characterized in that, The ultrafiltration membrane in the ultrafiltration device (7) is an external pressure PVDF hollow fiber membrane with a filtration flux of 40-60 L / m³. 2 ·h.

10. The system according to claim 1, characterized in that, The reverse osmosis device (9) adopts a one-stage two-stage process. The reverse osmosis membrane is selected from DuPont anti-fouling brackish water reverse osmosis membrane elements. The device has a recovery rate of 70% and a desalination rate of over 97%.

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