Non-ferrous metal resource recycling industry rain and sewage wastewater collaborative treatment method and system

Abstract

The application discloses a non-ferrous metal resource recycling industry rain and sewage wastewater collaborative treatment method and system, the rain and sewage wastewater includes rainwater, general production wastewater, waste acid wastewater and acid wastewater, and the method comprises the following steps: coagulating and depositing, filtering, low-pressure reverse osmosis desalination treatment on the rainwater and the general production wastewater, and the concentrated water of the reverse osmosis is used as the dosing water of lime milk of the waste acid wastewater and the acid wastewater; the waste acid wastewater and the acid wastewater are subjected to sulfuration reaction, neutralization treatment with the lime milk, softening, filtering, resin softening, reverse osmosis and evaporation crystallization treatment, the steam condensate of the evaporation is used as the reused water, and the salt crystallized by the evaporation is used for resource utilization. The application can realize zero discharge of the wastewater generated in the non-ferrous metal recycling process, does not discharge any wastewater to the outside world, and guarantees that the natural water body and the soil are not polluted.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wastewater treatment, in particular to a rain and sewage wastewater collaborative treatment method and system for non-ferrous metal resource recycling industry. BACKGROUND

[0002] In recent years, in response to the concept of green development, the non-ferrous metal resource recycling industry has developed rapidly. A large amount of wastewater containing heavy metals, arsenic and soluble salts and other heavy pollutants is generated in the process of non-ferrous metal resource recycling, which has become a threshold restricting the process of turning waste into treasure in the non-ferrous metal industry. Seeking a production wastewater treatment technology with better treatment effect, stronger process stability and lower operation cost, reducing wastewater discharge and achieving zero wastewater discharge has become the internal demand and external requirement of the development of non-ferrous metal resource recycling industry.

[0003] In the wastewater treatment system of non-ferrous metal smelting industry, the sources of wastewater are usually divided into initial rainwater and production wastewater; the production wastewater mainly includes waste acid wastewater, acid wastewater and general production wastewater, etc. The waste acid wastewater is mainly derived from the purification process in the process of metal smelting flue gas acid production, and the wastewater is strongly acidic with high heavy metal content; the main sources of acid wastewater are waste acid post-treatment liquid, laboratory wastewater, acid mist purification drainage, etc., and the wastewater is slightly acidic with high heavy metal content; the general wastewater refers to other wastewater discharged in the production process except waste acid wastewater and acid wastewater, mainly including concentrated salt water of desalting water station and softening water station, indirect cooling drainage, road and general ground washing water, etc., and the wastewater is close to neutral pH and contains a small amount of heavy metals.

[0004] At present, the conventional engineering design of wastewater is to mix the initial rainwater, general production wastewater, waste acid wastewater and acid wastewater together for treatment and then discharge after reaching the standard. However, for resource recycling plants, the above treatment method has great disadvantages: the reason is that the initial rainwater and general production wastewater have low heavy metal content, low soluble salt content and close to neutral pH, and the water quality is relatively good; the process wastewater (mainly waste acid wastewater and acid wastewater) has high arsenic and heavy metal content, high soluble salt content and poor water quality; mixing together for treatment will increase the operation cost of disposing wastewater, and also will increase the risk of non-compliance of rainwater.

[0005] At the same time, with the increase of environmental protection pressure and the increasingly strict environmental protection policy, the wastewater treatment of non-ferrous metal resource recycling plants generally requires zero discharge. SUMMARY

[0006] In view of the deficiencies in the prior art, the present application provides a rain and sewage wastewater collaborative treatment method and system for non-ferrous metal resource recycling industry.

[0007] The present invention also discloses a method for collaboratively treating rainwater, sewage and wastewater in the non-ferrous metal resource recovery industry. The rainwater, sewage and wastewater include rainwater, general production wastewater, acid wastewater and acidic wastewater. The collaborative treatment method comprises:

[0008] Collect rainwater and general production wastewater into regulating tanks for thorough mixing and homogenization;

[0009] The wastewater in the regulating tank is subjected to coagulation and sedimentation treatment;

[0010] The produced water after coagulation and sedimentation is subjected to a first multi-media filtration;

[0011] performing a first ultrafiltration on the produced water after the first multi-media filtration;

[0012] The water produced after the first ultrafiltration is subjected to low-pressure reverse osmosis desalination treatment, the desalinated water is used as recycled water, and the concentrated water with high salt content is used as lime preparation water for acid wastewater and acidic wastewater;

[0013] Collect the dirty acid wastewater and acid wastewater into the dirty acid tank, mix them thoroughly and homogenize them;

[0014] The waste water in the waste acid tank is subjected to sulfidation reaction treatment;

[0015] The water produced after the sulfidation reaction is neutralized with lime milk; wherein the lime milk is prepared by mixing lime with chemical water;

[0016] Softening the produced water after the neutralization reaction;

[0017] The produced water after the softening reaction is subjected to a second multi-media filtration;

[0018] subjecting the produced water after the second multi-media filtration to a second ultrafiltration;

[0019] The produced water after the second ultrafiltration is subjected to resin softening treatment;

[0020] The water softened by the resin is subjected to medium-pressure reverse osmosis desalination treatment, and the desalinated water is used as recycled water;

[0021] The high-salinity concentrated water after medium-pressure reverse osmosis is concentrated by high-pressure reverse osmosis, and the water produced by high-pressure reverse osmosis is used as recycled water;

[0022] The concentrated water after high-pressure reverse osmosis is evaporated and crystallized, the evaporated steam condensate is used as recycled water, and the evaporated crystallized salt is recycled.

[0023] As a further improvement of the present invention, it also includes: softening the remaining high-salt concentrated water after low-pressure reverse osmosis, the backwash wastewater of the second multi-media filter, the backwash wastewater of the second ultrafiltration device, the flushing wastewater of the weak cationic resin of the resin softening unit, and the regenerated wastewater.

[0024] As a further improvement of the present invention, the turbidity of the water produced by the first ultrafiltration is less than 0.2NTU and the SDI is less than 5.

[0025] As a further improvement of the present invention, the process of subjecting the wastewater in the waste acid tank to sulfidation reaction treatment comprises:

[0026] The wastewater in the dirty acid tank is sent to the reaction tank, and the sulfiding agent is added to the reaction tank. The sulfiding agent and the arsenic ions in the wastewater form arsenic sulfide precipitate; the wastewater after the reaction enters the thickener, and the wastewater stays in the thickener for not less than 12 hours. The precipitate is enriched at the bottom of the thickener and is pumped to the dehydration system. The arsenic-containing sludge filtered out is treated as hazardous waste; the removal rate of arsenic ions and heavy metals in the effluent of the sulfidation reaction is not less than 98%.

[0027] As a further improvement of the present invention, the neutralization treatment of the produced water after the sulfidation reaction with lime milk comprises:

[0028] The pH of the wastewater is adjusted to 3-8 by adding lime milk. Lime is dissolved in rainwater and high-salt concentrated water after low-pressure reverse osmosis of general industrial wastewater to obtain lime milk. During this process, fluoride ions react with calcium to produce precipitation, thereby removing fluoride ions from the raw water and ensuring that the fluoride ion content in the effluent does not exceed 20 mg / L. At the same time, sulfate and calcium ions are also precipitated in the form of gypsum, which is treated as general solid waste and the clear liquid is subjected to subsequent softening treatment.

[0029] As a further improvement of the present invention, the method further comprises: collecting part of the acidic wastewater directly into a sewage regulating tank, fully mixing and homogenizing it, and then performing a softening treatment.

[0030] The present invention also discloses a method for co-processing rainwater, sewage and wastewater in the non-ferrous metal resource recovery industry, which is used to implement the above-mentioned method for co-processing rainwater, sewage and wastewater in the non-ferrous metal resource recovery industry. The rainwater, sewage and wastewater include rainwater, general production wastewater, acid wastewater and acidic wastewater. The co-processing system includes:

[0031] The regulating tank, coagulation and sedimentation unit, first multi-media filter, first ultrafiltration device and low-pressure reverse osmosis unit are arranged in sequence along the treatment direction of rainwater and general industrial wastewater. The water produced by low-pressure reverse osmosis is used as recycled water, and the concentrated water of low-pressure reverse osmosis is used as lime preparation water for acid wastewater and acidic wastewater.

[0032] The waste acid tank, sulfidation reaction unit, neutralization reaction unit, softening unit, second multi-media filter, second ultrafiltration device, resin softening unit, medium-pressure reverse osmosis unit, high-pressure reverse osmosis unit and evaporation crystallization unit are arranged in sequence along the treatment direction of waste acid wastewater and acidic wastewater; the evaporated steam condensate is used as recycled water, and the salt evaporated and crystallized is used as a resource; among them, lime milk is added in the neutralization reaction unit, and the lime milk is prepared by lime and chemical water.

[0033] The present invention discloses

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The present invention is used for the comprehensive treatment of wastewater from non-ferrous metal resource recovery plants, which can achieve zero discharge of wastewater generated in the non-ferrous metal recovery process, without discharging any wastewater to the outside world, thus ensuring that natural water bodies and soil are not polluted.

[0036] 2. The present invention realizes the comprehensive treatment of wastewater from non-ferrous metal resource recovery plants and reduces treatment costs: rainwater, general production wastewater, dirty acid wastewater and acidic wastewater are treated separately to save operating costs; at the same time, the concentrated water from rainwater and general wastewater after membrane concentration is used as the mixing water for the dirty acid wastewater and acidic wastewater treatment process, without introducing fresh water from the outside, thereby reducing the wastewater volume of the entire plant, reducing the wastewater treatment cost, and realizing the comprehensive utilization of the wastewater of the entire plant.

[0037] 3. The present invention uses two-stage arsenic and heavy metal removal to ensure that the water quality meets the standards, while significantly reducing the output of hazardous waste, thereby reducing treatment costs: the two-stage arsenic and heavy metal removal method uses sulfidation + lime iron salt method: the first step is to use sulfidation to remove arsenic ions and heavy metals to a low content, and the second step is to use lime iron salt method to neutralize the acid wastewater and acidic wastewater, producing a large amount of calcium sulfate precipitation, and simultaneously removing the remaining arsenic and heavy metals in the wastewater. The present invention reduces the output of hazardous waste, and only a small amount of sludge generated in the sulfidation process is subjected to hazardous waste treatment, and the calcium sulfate produced by the lime iron salt method can be reused for production.

[0038] 4. The present invention adopts multi-stage concentration + MVR process for desalination to reduce the amount of evaporated water, and adopts negative pressure and low-temperature evaporation at the same time, with low operating costs: the medium-pressure reverse osmosis + high-pressure reverse osmosis process is used to first concentrate the wastewater, reducing the water intake of evaporation and crystallization, thereby reducing the processing scale of evaporation and crystallization, and the reverse osmosis water can be directly reused in the plant; the evaporation and crystallization system adopts low-temperature negative pressure evaporation to reduce steam and power consumption.

[0039] 5. The present invention effectively solves the problem of fouling and clogging of the reverse osmosis membrane during the high-concentration process: a two-stage softening process of soft reaction + resin softening is adopted to remove the calcium and magnesium hardness in the wastewater to below 1.5 mg / L, thereby ensuring that the reverse osmosis does not scale.

[0040] 6. According to the characteristics of water quality, the present invention can crystallize out some sodium sulfate, which can be used as a resource.

[0041] 7. All self-consumed water in the present invention is recycled without using fresh water, thus reducing water and treatment costs.

[0042] 8. The present invention returns the resin-softened regenerated water to the neutralization reaction for treatment, thereby reducing the amount of lime added while treating the regenerated wastewater.

[0043] 9. The water produced by the present invention can meet the water replenishment requirements of the factory water station and the circulating water station, realizing the recycling of water resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a flow chart of the method for collaboratively treating rainwater, sewage and wastewater in the non-ferrous metal resource recovery industry disclosed in the present invention;

[0045] Figure 2 This is a framework diagram of the rainwater, sewage and wastewater collaborative treatment system for the non-ferrous metal resource recovery industry disclosed in the present invention;

[0046] Figure 3 The present invention discloses a flow chart of a method for collaboratively treating rainwater, sewage and wastewater in the non-ferrous metal resource recovery industry according to an embodiment of the present invention.

[0047] In the picture:

[0048] 1. Equalization tank; 2. Coagulation and sedimentation unit; 3. First multi-media filter; 4. First ultrafiltration device; 5. Low-pressure reverse osmosis unit; 6. Sewage acid tank; 7. Sulfidation reaction unit; 8. Neutralization reaction unit; 9. Softening unit; 10. Second multi-media filter; 11. Second ultrafiltration device; 12. Resin softening unit; 13. Medium-pressure reverse osmosis unit; 14. High-pressure reverse osmosis unit; 15. Evaporation crystallization unit. DETAILED DESCRIPTION

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0050] The present invention is described in further detail below with reference to the accompanying drawings:

[0051] like Figure 1As shown, the present application provides a rain and sewage wastewater collaborative treatment method in non-ferrous metal resource recycling industry, the rain and sewage wastewater includes rainwater, general production wastewater, acid wastewater and acidic wastewater, the collaborative treatment method comprises:

[0052] S1, collecting rainwater and general production wastewater into a conditioning tank, fully mixing and homogenizing to reduce the risk of water quality fluctuation;

[0053] S2, coagulating and precipitating the wastewater in the conditioning tank to remove suspended solids, colloids and other impurities in the wastewater, and the generated sludge is used as general solid waste;

[0054] S3, the water produced after coagulation and precipitation is subjected to first multi-medium filtration to remove SS that has not been completely precipitated in the wastewater, thereby ensuring stable operation of the ultrafiltration device;

[0055] S4, the water produced after the first multi-medium filtration is subjected to first ultrafiltration to further remove insoluble substances in the wastewater, and the SDI of the water produced by the first ultrafiltration can be ensured to be not higher than 5, thereby ensuring normal operation of the low-pressure reverse osmosis;

[0056] S5, the water produced after the first ultrafiltration is subjected to low-pressure reverse osmosis desalination treatment, and the desalinated water can be directly reused as reuse water in the factory area, and the concentrated water with high salt content is used as lime dosing water for acid wastewater and acidic wastewater;

[0057] S6, collecting acid wastewater and acidic wastewater into an acid tank, fully mixing and homogenizing to reduce the risk of water quality fluctuation;

[0058] S7, the wastewater in the acid tank is subjected to sulfidation reaction treatment, heavy metals and arsenic ions are combined with sulfidation agents to precipitate out in the form of sulfidation slag, which is treated as hazardous waste to remove heavy metals and arsenic ions in the wastewater, and the removal rate of heavy metals and arsenic ions is as high as 98% or more;

[0059] S8, neutralizing the water produced after the sulfidation reaction with lime milk; wherein the lime milk is prepared by mixing lime with the dosing water; by adding lime to neutralize sulfuric acid in the wastewater, the lime can be dissolved by the concentrated water with high salt content after low-pressure reverse osmosis of the rainwater and general production wastewater, and added to the water produced after the sulfidation reaction and the neutralization reaction system in the form of lime milk; a large amount of Ca 2+ , Ca 2+ is introduced in the neutralization process to combine with sulfate ions to generate a large amount of calcium sulfate precipitate, which can be reused in the production unit according to the quality of the calcium sulfate;

[0060] S9, the water after neutralization reaction is softened; the concentrated water with high salt content after low-pressure reverse osmosis, the backwashing wastewater of the second multi-medium filter, the backwashing wastewater of the second ultrafiltration device, the washing wastewater and regeneration wastewater of the weak cation resin of the resin softening unit are softened; and part of the acidic wastewater is directly collected into a sewage conditioning tank, and after being fully mixed and homogenized, the acidic wastewater is subjected to softening treatment; wherein, by adding liquid alkali and soda ash, the calcium and magnesium hardness in the wastewater is removed, the calcium and magnesium ions combine with carbonate ions or hydroxyl ions to form a precipitate, and the softening residue is treated as general solid waste; the total hardness of the water produced by the softening reaction is not more than 150 mg / L, and the SS is less than or equal to 30 mg / L;

[0061] S10, the water produced after the softening reaction is subjected to second multi-medium filtration to remove the SS in the wastewater that has not been completely precipitated, so as to ensure stable operation of the ultrafiltration device;

[0062] S11, the water produced after the second multi-medium filtration is subjected to second ultrafiltration to further remove the insoluble substances in the wastewater, and the SDI of the water produced by the ultrafiltration can be ensured to be not higher than 5, so as to ensure normal operation of the low-pressure reverse osmosis;

[0063] S12, the water produced after the second ultrafiltration is subjected to resin softening treatment; wherein, the resin softening treatment is to further remove the residual Ca 2+ , Mg 2+ in the concentrated brine through the selective exchange of the weak acid cation exchange resin in the resin tank, so as to prevent the calcium and magnesium ions from being multiplied in the high-concentration process, resulting in membrane fouling of the reverse osmosis;

[0064] S13, the water produced after the resin softening is subjected to desalination treatment by medium-pressure reverse osmosis, and the water produced after desalination can be directly reused as reuse water in the factory area;

[0065] S14, the concentrated water with high salt content after the medium-pressure reverse osmosis is subjected to high-pressure reverse osmosis concentration treatment, and the high-pressure reverse osmosis continues to concentrate the wastewater, and the water produced by the high-pressure reverse osmosis can be directly reused as reuse water in the factory area;

[0066] S15, the concentrated water after the high-pressure reverse osmosis is subjected to evaporation crystallization treatment, the steam condensate produced by evaporation can be directly reused as reuse water in the factory area, and the salt (sodium sulfate) produced by evaporation crystallization is resourceized.

[0067] As shown in Figure 2 , the present application provides a rain and sewage wastewater collaborative treatment method in non-ferrous metal resource recycling industry, which is used to realize the rain and sewage wastewater collaborative treatment method in non-ferrous metal resource recycling industry, the rain and sewage wastewater includes rainwater, general production wastewater, waste acid wastewater and acidic wastewater, the collaborative treatment system comprises:

[0068] The regulating tank 1, coagulation and sedimentation unit 2, first multi-media filter 3, first ultrafiltration device 4 and low-pressure reverse osmosis unit 5 are arranged in sequence along the treatment direction of rainwater and general industrial wastewater. The produced water of low-pressure reverse osmosis is used as recycled water, and the concentrated water of low-pressure reverse osmosis is used as lime preparation water for acid wastewater and acid wastewater.

[0069] Along the treatment direction of the waste acid wastewater and the acidic wastewater, there are arranged in sequence a waste acid tank 6, a sulfidation reaction unit 7, a neutralization reaction unit 8, a softening unit 9, a second multi-media filter 10, a second ultrafiltration device 11, a resin softening unit 12, a medium-pressure reverse osmosis unit 13, a high-pressure reverse osmosis unit 14 and an evaporation crystallization unit 15; the evaporated steam condensate is used as recycled water, and the salt evaporated and crystallized is utilized as a resource; wherein, lime milk is added to the neutralization reaction unit, and the lime milk is prepared by mixing lime and prepared water.

[0070] Example:

[0071] The present invention is used to treat rainwater and sewage from a multi-metal resource recovery and comprehensive utilization project; wherein,

[0072] This project is a zero-discharge project for clean wastewater and process wastewater in the entire factory area. Clean wastewater includes initial rainwater, chemical water concentrate, indirect cooling drainage, workshop washing water, ground washing water, etc.; process wastewater includes polluted acid wastewater, gold separation wastewater, silver separation wastewater after workshop treatment, acid mist absorption wastewater, laboratory wastewater, drying wastewater, car wash and bag washing leachate, etc.

[0073] (1) Influent water quality:

[0074] Clean wastewater: pH is 6-7, neutral; COD is about 20 mg / L; total salt content is about 1000 mg / L; calcium ion content is about 25 mg / L; magnesium ion content is about 11 mg / L; sulfate content is 80 mg / L; chloride content is 150 mg / L;

[0075] Acid wastewater: contains 3% to 4% sulfuric acid; COD is about 50 mg / L; zinc ion content is about 6000 mg / L; nickel ion content is about 200 mg / L; copper ion content is about 2000 mg / L; silver ion content is about 1.0 mg / L; arsenic ion content is about 5000 mg / L; chloride content is about 3000 mg / L; fluoride ion content is about 2300 mg / L;

[0076] (2) Outlet water quality:

[0077] The produced water meets the process and product water - raw water standards of the "Water Quality for Industrial Water Used in Municipal Wastewater Recycling" (GB / T19923-2005), as shown in Table 1. It also meets the requirements of the "Emission Standard for Pollutants from Recycled Copper, Aluminum, Lead, and Zinc Industries" (GB31574-2015), as shown in Table 2. Hydrogen sulfide emissions from the sulfidation area's decontamination tower meet the requirements of the "Emission Standard for Odor Pollutants" (GB14554-93). The discharge rate is less than 0.33 kg / h, and the high-salt water is equipped with an MVR evaporation unit.

[0078] Table 1

[0079]

[0080] Table 2

[0081]

[0082] (3) Specific methods and systems for the coordinated treatment of rainwater, sewage and wastewater, including:

[0083] 1) The treatment process for clean wastewater is:

[0084] Initial rainwater, workshop wash water, floor flushing water, chemical concentrate, and indirect cooling water are collected in the clean wastewater regulating tank. After homogenization in the clean wastewater regulating tank, it is pumped to the coagulation and sedimentation unit. Sodium sulfide, liquid caustic soda, PFS, PAM, etc. are added to remove heavy metals and suspended solids in the water. The precipitate after coagulation and sedimentation is filtered and anode plates are cast. The heavy metal removal rate of the produced water is not less than 99%, and the suspended solids do not exceed 30mg / L.

[0085] The effluent from the coagulation and sedimentation reaction flows through a centrifugal pump into the first multi-media filter, where suspended particles and colloids are further removed. The product water from the first multi-media filtration passes through the first ultrafiltration device (ultrafiltration membrane) to remove suspended matter, colloids, and microorganisms. The effluent turbidity is less than 0.2 NTU and the SDI is less than 5, ensuring the normal and stable operation of the subsequent low-pressure reverse osmosis unit.

[0086] Low-pressure reverse osmosis desalinates wastewater, and the produced water meets the reuse water standard and is sent to the reuse water production pool. The TDS of the concentrated water from low-pressure reverse osmosis is about 4000 mg / L, which can be used as lime preparation water for the process wastewater system to prepare lime milk and add it to the neutralization reaction unit of the process wastewater.

[0087] 2) The treatment process of process wastewater is:

[0088] The acid wastewater, gold separation wastewater, silver separation wastewater, and car wash and bag washing leachate are collected in the acid waste tank and then sent to the sulfidation reaction unit. The sulfiding agent is added to the reaction tank of the sulfidation reaction unit to form arsenic sulfide precipitate with arsenic ions. The wastewater after the reaction enters the thickener. The wastewater stays in the thickener for not less than 12 hours. The precipitate is enriched at the bottom of the thickening tank and is pumped to the dehydration system. The arsenic-containing sludge filtered out is treated as hazardous waste, and the hydrogen sulfide generated during the reaction is absorbed and treated. The removal rate of arsenic ions and heavy metals in the effluent from the sulfidation reaction is not less than 98%.

[0089] The water produced by the sulfidation reaction is sent to the neutralization reaction unit, and the pH of the wastewater is adjusted to 3-8 by adding lime. During this process, fluoride ions will be precipitated with calcium in large quantities, and the fluoride ions in the raw water are removed. The fluoride ions in the effluent do not exceed 20 mg / L; at the same time, sulfate and calcium ions are also precipitated in the form of gypsum. The gypsum can be treated as general solid waste, and the clear liquid is sent to the softening unit for softening treatment.

[0090] Acid mist absorption wastewater, laboratory wastewater, and drying wastewater are sent to the sewage regulating tank, where they are aerated, mixed, and homogenized before being sent to the softening unit for softening treatment. At the same time, the backwash wastewater from the second multi-media filter in the process wastewater system, the backwash wastewater from the second ultrafiltration device (ultrafiltration membrane), the flushing wastewater from the weak cationic resin in the resin softening unit, and the regeneration wastewater are also sent to the softening unit. In the softening unit, the pH of the inlet water is adjusted by adding sodium hydroxide, and a soda ash solution is added to react with the CO2 and HCO in the water. 3- , Ca 2+ Mg 2+ The reaction generates CaCO3 and Mg(OH)2 precipitates. Simultaneously, PFS and PAM are added to form larger flocs, effectively removing suspended solids from the produced water. The softening reaction produces water with a total calcium and magnesium hardness of no more than 120 mg / L, an alkalinity of approximately 300 mg / L, and SS no higher than 30 mg / L. Finally, after pH adjustment by adding acid to the effluent area, the effluent is collected in a sump and fed into subsequent treatment structures.

[0091] The softening unit's effluent flows through a centrifugal pump into the second multi-media filter, where suspended particles and colloids are further removed. The second multi-media filter's output water is filtered through the second ultrafiltration device (ultrafiltration membrane), effectively removing suspended matter, colloids, and microorganisms. The effluent turbidity is less than 0.2 NTU, and the SDI is less than 5, ensuring the normal and stable operation of the subsequent treatment system.

[0092] The water produced by the second ultrafiltration device enters the weak acid cation bed, which uses the selective exchange of the cation exchange resin in the resin tank to remove the residual Ca in the concentrated brine. 2+ Mg 2+Thoroughly remove the hardness of the water produced by the weak acid cation bed, and the total hardness is no more than 1.5 mg / L, ensuring the long-term stable operation of the entire device.

[0093] The water produced by the weak acid cation bed undergoes secondary concentration and desalination through medium-pressure and high-pressure reverse osmosis. The water is then sent to a reuse pool for on-site reuse. The highly concentrated brine, with a TDS of 100,000 mg / L, is then sent to the MVR for evaporation and crystallization. The steam condensate from the MVR is then sent to a reuse pool for on-site reuse. The sodium sulfate produced by the MVR can be recycled.

[0094] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for co-processing rainwater, sewage and wastewater in the non-ferrous metal resource recovery industry, wherein the rainwater, sewage and wastewater include rainwater, general production wastewater, acid wastewater and acidic wastewater, characterized in that: The collaborative processing method comprises: Collect rainwater and general production wastewater into regulating tanks for thorough mixing and homogenization; The wastewater in the regulating tank is subjected to coagulation and sedimentation treatment; The produced water after coagulation and sedimentation is subjected to a first multi-media filtration; performing a first ultrafiltration on the produced water after the first multi-media filtration; The water produced after the first ultrafiltration is subjected to low-pressure reverse osmosis desalination treatment, the desalinated water is used as recycled water, and the concentrated water with high salt content is used as lime preparation water for acid wastewater and acidic wastewater; Collect the dirty acid wastewater and acid wastewater into the dirty acid tank, mix them thoroughly and homogenize them; The wastewater in the waste acid tank is subjected to a sulfidation reaction treatment. Specifically, the wastewater in the waste acid tank is sent to a reaction tank, and a sulfiding agent is added to the reaction tank. The sulfiding agent reacts with the arsenic ions in the wastewater to form arsenic sulfide precipitates. The wastewater after the reaction enters a thickener, where it stays for at least 12 hours. The precipitate accumulates at the bottom of the thickener and is pumped to a dehydration system. The arsenic-containing sludge filtered out is treated as hazardous waste. The removal rate of arsenic ions and heavy metals in the effluent from the sulfidation reaction is at least 98%. The produced water after the sulfidation reaction is neutralized with lime milk, which is prepared by mixing lime with chemical water. Specifically, the wastewater pH is adjusted to a range of 3-8 by adding lime milk. Lime is dissolved in rainwater and high-salt concentrated water from low-pressure reverse osmosis of general industrial wastewater to produce lime milk. During this process, fluoride ions react with calcium to produce precipitation, thereby removing fluoride ions from the raw water and reducing the fluoride ion content of the effluent to no more than 20 mg / L. At the same time, sulfate and calcium ions are also precipitated in the form of gypsum, which is treated as general solid waste, and the clear liquid is subsequently softened. Softening the produced water after the neutralization reaction; The produced water after the softening reaction is subjected to a second multi-media filtration; subjecting the produced water after the second multi-media filtration to a second ultrafiltration; The produced water after the second ultrafiltration is subjected to resin softening treatment; The water softened by the resin is subjected to medium-pressure reverse osmosis desalination treatment, and the desalinated water is used as recycled water; The high-salinity concentrated water after medium-pressure reverse osmosis is concentrated by high-pressure reverse osmosis, and the water produced by high-pressure reverse osmosis is used as recycled water; The concentrated water after high-pressure reverse osmosis is evaporated and crystallized, the evaporated steam condensate is used as recycled water, and the evaporated crystallized salt is recycled.

2. The method for co-processing rainwater, sewage and wastewater in the non-ferrous metal resource recovery industry according to claim 1, characterized in that: Also includes: The remaining concentrated water with high salt content after low-pressure reverse osmosis, the backwash wastewater of the second multi-media filter, the backwash wastewater of the second ultrafiltration device, the flushing wastewater of the weak cationic resin of the resin softening unit and the regenerated wastewater are softened.

3. The method for co-processing rainwater, sewage and wastewater in the non-ferrous metal resource recovery industry according to claim 1 or 2, characterized in that: The turbidity of the water produced by the first ultrafiltration is less than 0.2NTU and the SDI is less than 5.

4. The method for co-processing rainwater, sewage and wastewater in the non-ferrous metal resource recovery industry according to claim 1 or 2, characterized in that: Also includes: Part of the acidic wastewater is directly collected into the sewage equalization tank, fully mixed and homogenized, and then softened.

5. A rainwater, sewage and wastewater coordinated treatment system for the non-ferrous metal resource recovery industry, used to implement the rainwater, sewage and wastewater coordinated treatment method for the non-ferrous metal resource recovery industry as described in any one of claims 1 to 4, wherein the rainwater, sewage and wastewater include rainwater, general production wastewater, acid wastewater and acidic wastewater, and characterized in that: The collaborative processing system comprises: The regulating tank, coagulation and sedimentation unit, first multi-media filter, first ultrafiltration device and low-pressure reverse osmosis unit are arranged in sequence along the treatment direction of rainwater and general industrial wastewater. The water produced by low-pressure reverse osmosis is used as recycled water, and the concentrated water of low-pressure reverse osmosis is used as lime preparation water for acid wastewater and acidic wastewater. The waste acid tank, sulfidation reaction unit, neutralization reaction unit, softening unit, second multi-media filter, second ultrafiltration device, resin softening unit, medium-pressure reverse osmosis unit, high-pressure reverse osmosis unit and evaporation crystallization unit are arranged in sequence along the treatment direction of waste acid wastewater and acidic wastewater; the evaporated steam condensate is used as recycled water, and the salt evaporated and crystallized is used as a resource; among them, lime milk is added in the neutralization reaction unit, and the lime milk is prepared by lime and chemical water.

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