Advanced treatment process for ammonia distillation wastewater

Abstract

The invention relates to an advanced treatment process for ammonia distillation wastewater. Which comprises ammonia distillation wastewater pretreatment, biochemical treatment, advanced treatment, recycling treatment, concentrated water treatment and sludge treatment, and is characterized in that in the biochemical treatment stage, the pretreated wastewater enters an aerobic tank for phenol degradation treatment; then passing through a two-stage A / O biochemical system; and adding an adsorption coagulant into the effluent through a sedimentation tank. The method systematically solves the problems of incomplete pollutant removal, resource waste and high energy consumption in ammonia distillation wastewater treatment, realizes multiple technical breakthroughs of water quality standard reaching, resource recovery and cost optimization, and is suitable for industrial advanced treatment of high-concentration organic ammonia nitrogen wastewater in industries such as coking and metallurgy.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial wastewater treatment, and in particular to a deep treatment process for ammonia distillation wastewater. Background Art

[0002] Ammonia evaporation wastewater is a typical highly polluted wastewater generated during the production process of industries such as coking and metallurgy. Its water quality is characterized by high pollutant concentrations, complex components, and poor biodegradability. This type of wastewater not only contains high concentrations of organic matter (COD ≤ 5400 mg / L), ammonia nitrogen (NH3-N ≤ 100 mg / L), and volatile phenols (≤ 1200 mg / L), but also has high salt content (TDS = 5780 mg / L) and complex components (such as cyanide, oils, and polycyclic aromatic hydrocarbons). This makes it difficult for traditional single treatment processes to achieve efficient removal of pollutants and resource recovery. In addition, the wastewater has poor biodegradability (B / C ratio is often less than 0.3) and phenolic substances have a significant inhibitory effect on microorganisms, further increasing the difficulty of biochemical treatment. If this type of wastewater is directly discharged without effective treatment, it will pose a serious threat to water ecology and human health. Traditional treatment processes, due to the lack of systematic integrated design, are difficult to achieve efficient removal of pollutants and resource recovery.

[0003] Currently, the treatment processes for ammonia wastewater mainly focus on physical, chemical, and biological methods, but all of them have significant shortcomings. The core issues are summarized as follows: 1. Insufficient coordination between pretreatment and biochemical treatment, resulting in incomplete pollutant removal: In traditional processes, physical methods (such as oil separation and flotation) can only remove some oils and suspended solids, and the removal rate of core pollutants such as phenols and ammonia nitrogen is insufficient, making the subsequent biochemical system susceptible to high concentrations of toxic substances. The single-stage biochemical process has insufficient removal efficiency for ammonia nitrogen, total nitrogen and phenols, and cannot meet emission standards such as GB / T50050-2017; 2. Serious waste of resources: Although existing membrane treatment processes (such as single reverse osmosis) can achieve water purification, the concentrated water has a high salt content, and the direct discharge or treatment costs are high. Traditional evaporation and crystallization technology does not use salt separation technology, resulting in high salt production (often exceeding 30%) and generally high energy consumption. It does not achieve effective separation and recovery of salts (sodium sulfate, sodium chloride), resulting in high salt production, which violates the principle of "reduction and resource utilization"; 3. Low process integration and high operating costs: The simple stacking of single treatment units results in lengthy processes and poor synergy. In traditional processes, pH adjustment is not integrated with biochemical treatment, resulting in high alkali consumption. Sludge treatment fails to achieve volume reduction, with a moisture content exceeding 80%, increasing subsequent disposal costs and environmental risks.

[0004] Therefore, there is an urgent need to systematically solve the problems of incomplete pollutant removal, resource waste and high energy consumption in the treatment of ammonia wastewater, and to provide new methods and processes for the green treatment of industrial wastewater. Summary of the Invention

[0005] The purpose of this application is to provide a method for treating chemical ammonia distillation wastewater, effectively removing refractory organic pollutants and ammonia nitrogen, improving effluent quality, and realizing resource recovery to reduce resource waste and high energy consumption.

[0006] In order to achieve the above-mentioned invention objectives, this application adopts the following technical solutions: A deep treatment process for ammonia evaporation wastewater includes ammonia evaporation wastewater pretreatment, biochemical treatment, reuse treatment, concentrated water treatment and sludge treatment. In the biochemical treatment stage, the pretreated wastewater enters an aerobic tank for phenol reduction treatment; then passes through a two-stage A / O biochemical system; the effluent is then added with an adsorption coagulant in a sedimentation tank, and the effluent from the sedimentation tank is then catalytically oxidized by ozone.

[0007] Through the integrated process of ammonia wastewater pretreatment, biochemical treatment, membrane reuse, concentrated water treatment and sludge reduction treatment, we can achieve efficient removal of pollutants such as COD, ammonia nitrogen, phenols, etc. in wastewater, so that the effluent quality meets the standards for reuse, and solve the problems of incomplete pollutant removal, resource waste and high energy consumption in existing processes.

[0008] Furthermore, the adsorption coagulant is polyferric sulfate, activated carbon, nonionic polyacrylamide or a combination thereof.

[0009] Composite adsorption coagulants improve the adsorption efficiency of pollutants and are suitable for the treatment of high-phenol and high-turbidity wastewater.

[0010] Furthermore, the adsorption coagulant is polyferric sulfate, activated carbon and non-ionic polyacrylamide in a mass ratio of (150-200):(40-70):(1-2); and the adsorption coagulant is added in an amount of 250-650 mg / L per liter of wastewater.

[0011] Furthermore, the adsorption coagulant is polyferric sulfate, activated carbon and non-ionic polyacrylamide in a mass ratio of 180:50:1.5.

[0012] Optimize the coagulant ratio and dosage to achieve the best flocculation effect and cost balance at a dosage of 250-650 mg / L.

[0013] Furthermore, the two-stage A / O biochemical system includes a primary A / O unit and a secondary A / O unit connected in sequence; the primary A / O unit includes: an anoxic tank: dissolved oxygen ≤ 0.5 mg / L, hydraulic retention time of 10-14 hours, and sludge return ratio of 100%-200%; an aerobic tank: dissolved oxygen 2-4 mg / L, and hydraulic retention time of 12-16 hours; Secondary A / O unit: anoxic tank: dissolved oxygen ≤ 0.5 mg / L, hydraulic retention time is 8-12 hours, sludge return ratio is 50%-100%; aerobic tank: dissolved oxygen is 2-4 mg / L, hydraulic retention time is 10-14 hours.

[0014] Optimize the two-stage A / O system to control dissolved oxygen and residence time in sections to improve the removal rates of total nitrogen and ammonia nitrogen.

[0015] Furthermore, in the pretreatment stage of ammonia vapor wastewater, the ammonia vapor wastewater enters the regulating tank and passes through the oil separator and flotation equipment in sequence to remove heavy oil and emulsified oil, and then adjusts the pH to 6.5-7.5.

[0016] Pretreatment to remove oil and adjust pH to reduce subsequent biochemical load Furthermore, in the reuse treatment stage, the wastewater after biochemical treatment passes through a high-density sedimentation tank to remove hardness, suspended matter and oil, and then passes through a filter, an ultrafiltration membrane system and a reverse osmosis membrane system in sequence. The produced water is reused after meeting the standards.

[0017] Membrane reuse treatment ensures that the produced water quality meets the standards and realizes the recycling of water resources.

[0018] Furthermore, in the concentrated water treatment stage, the concentrated water section is separated into divalent salts and monovalent salts through the first-level nanofiltration. After the nanofiltration water is concentrated by the first-level reverse osmosis, it enters the sodium sulfate and sodium chloride evaporation and crystallization systems respectively to recover sodium sulfate and sodium chloride.

[0019] Concentrated water salt crystallization is used to recover industrial salt, with the amount of impurities being ≤15%, thus realizing resource recycling and reducing the cost of hazardous waste treatment.

[0020] Furthermore, in the sludge treatment stage, the sludge in the sedimentation tank is concentrated and dehydrated, the mud cake is sent to the coal blending system, and the filtrate is returned to the regulating tank.

[0021] Sludge is reduced and reused, and the filtrate is recycled to avoid secondary pollution.

[0022] A further ammonia evaporation wastewater deep treatment process specifically comprises the following steps: S1. Preprocessing stage: The ammonia wastewater enters the regulating tank and passes through the oil separator and flotation equipment in turn to remove heavy oil and emulsified oil, and then adjusts the pH to 7.0; S2. Biochemical treatment stage: The wastewater enters a high-load aerobic tank for phenol reduction treatment; then passes through a two-stage A / O biochemical system to achieve COD and ammonia nitrogen removal; The effluent is then fed through a sedimentation tank and adsorbed with coagulant; The effluent from the sedimentation tank is then catalytically oxidized by ozone to further reduce COD; The two-stage A / O biochemical system comprises a primary A / O unit and a secondary A / O unit connected in sequence; Primary A / O unit: anoxic tank: dissolved oxygen ≤ 0.5 mg / L, hydraulic retention time 12 hours, sludge return ratio 150%; aerobic tank: dissolved oxygen 4 mg / L, hydraulic retention time 14 hours; Secondary A / O unit: anoxic tank: dissolved oxygen ≤ 0.5 mg / L, hydraulic retention time of 10 hours, sludge return ratio of 75%; aerobic tank: dissolved oxygen 3 mg / L, hydraulic retention time of 12 hours; The adsorption coagulant is polyferric sulfate, activated carbon and non-ionic polyacrylamide in a mass ratio of 180:50:1.5, and the adsorption coagulant is added in an amount of 500 mg / L; S3. Recycling and processing stage: The reuse treatment stage includes high-density sedimentation tanks, filters, ultrafiltration membrane systems and reverse osmosis membrane systems.

[0023] After biochemical treatment, the wastewater is passed through a high-density sedimentation tank to remove hardness, suspended solids and oil, and then passes through a filter, ultrafiltration system and reverse osmosis membrane system in sequence. The produced water is reused after meeting the standards. S4. Brine treatment stage: The concentrated water section is separated into divalent salts and monovalent salts through the first-stage nanofiltration. The nanofiltration water is concentrated by the first-stage reverse osmosis and then enters the sodium sulfate and sodium chloride evaporation and crystallization systems respectively to recover sodium sulfate and sodium chloride; S5. Sludge treatment stage: The sludge in the sedimentation tank is concentrated and dehydrated, the mud cake is sent to the coal blending system, and the filtrate is returned to the regulating tank.

[0024] The present invention systematically solves the problems of incomplete pollutant removal, resource waste and high energy consumption in the treatment of ammonia wastewater through the full-process innovation of "pretreatment - biochemical dephenolization and denitrification - membrane salt separation - evaporation and crystallization - sludge reuse", and achieves multiple technological breakthroughs in water quality compliance, resource recovery and cost optimization. It is suitable for the industrial deep treatment of high-concentration organic ammonia nitrogen wastewater in coking, metallurgy and other industries. DETAILED DESCRIPTION

[0025] The present application is further described below through specific embodiments, but the embodiments are only basic descriptions of the inventive concept of the present application, and any equivalent transformations made based on the technical solution of the present application should fall within the scope of protection of the present invention.

[0026] Example 1: Typical ammonia wastewater treatment (design scale 50m 3 / h) 1. Influent water quality project COD <![CDATA[NH3-N]]> Volatile phenols Oils SS pH TDS Design indicators ≤5400 ≤100 ≤1200 ≤100 ≤300 7-10 5780 Actual water inflow 5200 95 1100 85 280 8.5 5600 2. Preprocessing stage (S1) Grease trap: residence time 2h, heavy oil removal rate 85%, oil content in effluent reduced to 12mg / L; Flotation equipment: Adding polyferric sulfate (300mg / L) + non-ionic polyacrylamide (1.5mg / L), the removal rate of light oil and emulsified oil is 92%, the oil content in the effluent is ≤5mg / L, and SS is ≤50mg / L; pH adjustment: Add sulfuric acid to adjust the pH to 7.0 to neutralize alkaline substances in advance, optimize the existence form of ammonia nitrogen, and reduce pH fluctuations in nitrification reactions.

[0027] 3. Biochemical treatment stage (S2) High-load aerobic tank: residence time 8h, dissolved oxygen 3mg / L, volatile phenol removal rate 96%, volatile phenol in effluent ≤30mg / L; two-stage A / O system: Level 1 A / O unit: Anoxic tank: residence time 12h, dissolved oxygen 0.3mg / L, sludge return ratio 150%, total nitrogen removal rate 55%, COD reduced to 1800mg / L; Aerobic pool: residence time 14h, dissolved oxygen 3mg / L, ammonia nitrogen removal rate 92%, effluent ammonia nitrogen ≤8mg / L; Secondary A / O unit: Anoxic tank: residence time 10h, dissolved oxygen 0.2mg / L, sludge return ratio 75%, total nitrogen further removed 30%, total nitrogen ≤15mg / L; Aerobic pool: residence time 12h, dissolved oxygen 2.5mg / L, COD reduced to 280mg / L; Sedimentation tank: Add composite adsorption coagulant: polyferric sulfate, activated carbon and non-ionic polyacrylamide in a mass ratio of 180:50:1.5, with a dosage of 500 mg / L (per liter of wastewater); SS removal rate of 95%, effluent SS ≤ 8 mg / L, COD ≤ 250 mg / L; Ozone catalytic oxidation: ozone dosage 25 mg / L, contact time 30 min, COD dropped to below 60 mg / L.

[0028] 4. Recycling and processing stage (S3) High-density sedimentation tank: Adding hardness removal agent (CaO+Na2CO3), calcium hardness is reduced to 150mg / L, suspended solids ≤5mg / L; ultrafiltration + reverse osmosis: Ultrafiltration membrane molecular weight cut-off 50kDa, SDI ≤ 3; The reverse osmosis membrane desalination rate is 98.5%, the produced water TDS is 80mg / L, COD is 45mg / L, ammonia nitrogen is 1.2mg / L, the recycling rate is 75%; the concentrated water output is 12.5m 3 / h, TDS=22000mg / L.

[0029] 5. Brine treatment stage (S4) Two-stage nanofiltration salt separation: First-stage nanofiltration: intercepts sodium sulfate, increases the sodium sulfate concentration of concentrated water to 15%, and produces water with a sodium chloride concentration of 8%; Secondary reverse osmosis membrane: further separates monovalent salts, and the sodium chloride concentration of concentrated water is increased to 20%; Multi-effect evaporation crystallization: Sodium sulfate evaporation: using the waste heat of the plant (steam temperature 80℃), it produces sodium sulfate with a purity of 98.2% and a mixed salt content of 12%. Sodium chloride evaporation: it produces sodium chloride with a purity of 98.8% and a total mixed salt content of ≤15%.

[0030] 6. Sludge treatment stage (S5) After the sedimentation tank sludge is filtered through plate and frame, the mud cake has a moisture content of 58% and a calorific value of 1600kcal / kg and is sent to the coal blending system; The filtrate is returned to the regulating tank for recycling treatment.

[0031] 7. Final effluent quality project COD <![CDATA[NH3-N]]> suspended matter Oils TDS pH Total nitrogen Measured value 45mg / L 1.2mg / L 6mg / L 0.8mg / L 80mg / L 7.8 12mg / L Standard value ≤60mg / L ≤5mg / L ≤10mg / L ≤5mg / L ≤1000mg / L 6-9 ≤15mg / L 8. Resource recovery and energy consumption Industrial salt: sodium sulfate, sodium chloride, miscellaneous salts (accounting for 12%); Energy consumption: Multi-effect evaporation energy consumption is 75kW·h / ton of water, and the overall energy consumption of the whole process is 0.75kW·h / m 3 wastewater; Cost: operating cost 4.8 yuan / m 3 Wastewater is reduced by 22% compared with traditional processes.

[0032] 9. Durability design of membrane system Ultrafiltration membrane components: Made of anti-pollution PVDF material, with a design flux of 40-60L / (m 2 h), perform chemical cleaning (CIP) regularly: Alkaline washing (NaOH solution, pH=12): Clean once every 72 hours to remove organic contamination; Acid cleaning (HCl solution, pH = 2): Clean once every 168 hours of operation to remove metal ion scaling; Reverse osmosis membrane system: Install a safety filter and antiscalant dosing device, combined with concentrated water reflux technology, to reduce the polarization of salt concentration on the membrane surface, delay the scaling of calcium and magnesium ions, and extend the membrane element cleaning cycle to once every three months.

[0033] Example 2: High-load impact condition treatment (influent ammonia nitrogen 150 mg / L) 1. Fluctuation of influent water quality COD = 5800 mg / L, NH3-N = 150 mg / L (50% more than the design value), volatile phenol = 1300 mg / L, oil = 120 mg / L.

[0034] 2. Process adjustment pretreatment: Flotation equipment: Add 640mg / L of polyferric sulfate and 3mg / L of non-ionic polyacrylamide, and the oil removal rate is increased to 93%; Two-stage A / O system: The retention time of the first-stage anoxic tank was extended to 14 hours, the sludge return ratio was increased to 200%, and 100 mg / L of sodium acetate COD equivalent was added; the dissolved oxygen in the second-stage aerobic tank was increased to 3.5 mg / L to enhance nitrification. Brine treatment: Nanofiltration salt separation adds a first-level membrane component to ensure that the amount of impurities is ≤15%.

[0035] 3. Treatment effect: effluent ammonia nitrogen = 4.5mg / L, COD = 58mg / L, total nitrogen = 14mg / L, all indicators meet the standards; System recovery time: 48 hours, and the impact resistance is significantly better than the single-stage A / O process.

[0036] Example 3: Sludge reduction and reuse 1. Sludge treatment parameters Sedimentation tank sludge production: 8m 3 / d (water content 95%); The mud cake output after concentration and dehydration is 4.2t / d (moisture content 60%), with a calorific value of 1550kcal / kg. The filtrate COD = 350 mg / L, ammonia nitrogen = 10 mg / L, and it has no significant impact on the system after being returned to the equalization tank.

[0037] 2. Resource Utilization The mud cake is mixed back into coking coal at a ratio of 5%, replacing part of the energy and saving about 200 tons of standard coal annually; Reduce sludge disposal costs.

[0038] 3. Reliability of sludge treatment system Plate and frame filter press: It adopts automatic plate-pulling diaphragm filter press, the filter cloth is made of polypropylene monofilament, and the compressive strength is ≥1.2MPa. The moisture content of the mud cake can be stably controlled below 60%, avoiding the problem of decreased dehydration efficiency caused by filter cloth clogging in traditional belt filter presses; Impact of filtrate circulation: After long-term monitoring, after the sludge filtrate is returned to the equalization tank, the COD fluctuation of the system water is <5%, and the ammonia nitrogen fluctuation is <3%, which has no significant impact on the overall treatment effect, proving that the sludge treatment link is sustainable.

[0039] experiment: 1. Experimental Purpose The effect of adsorption coagulant in the treatment of ammonia wastewater was verified by comparing single agent and different ratio combinations.

[0040] Compare the pollutant removal effects of composite adsorption coagulants and single agents (such as polyferric sulfate, activated carbon, and polyacrylamide); The synergistic removal of phenols, COD, and suspended solids (SS) at the optimal mass ratio (180:50:1.5) was verified; Analyze the impact of compound reagents on subsequent biochemical systems (two-stage A / O), such as microbial activity, sludge characteristics, etc.

[0041] 2. Experimental Design 1. Experimental Grouping 2. Experimental Procedure Preprocessing stage: Take ammonia wastewater (COD = 5200 mg / L, volatile phenol = 1100 mg / L, SS = 280 mg / L, oil = 85 mg / L), and add each group of reagents respectively; Rapid stirring (200 r / min, 2 min) → slow stirring (50 r / min, 15 min) → sedimentation for 30 min, take the supernatant to determine the water quality indicators.

[0042] Subsequent biochemical simulation: The pretreated effluent from each group was connected to a two-stage A / O system (simulation parameters: first-stage A / O residence time 26 h, second-stage A / O residence time 22 h); After 72 h of operation, the biochemical effluent COD, ammonia nitrogen, total nitrogen and sludge activity (characterized by sludge dehydrogenase activity SDH) were measured.

[0043] 3. Key testing indicators and methods 4. Experimental Results and Analysis 1. Pollutant removal effect in the pretreatment stage analyze: The synergistic effect of the composite agents was significant: the COD, volatile phenol and SS removal rates of the experimental group F were increased by 53%, 28% and 27% respectively compared with the single agent A, indicating that the flocculation effect of polyferric sulfate, the adsorption effect of activated carbon and the bridging effect of PAM formed a synergistic effect to effectively remove colloids, organic matter and suspended matter.

[0044] Effect of lack of PAM or activated carbon: The removal rates of the comparison groups D (lacking PAM) and E (lacking activated carbon) were reduced by 23% and 28% respectively, indicating that PAM enhances the floc strength and activated carbon supplements the adsorption of small molecular organic matter, and both are indispensable.

[0045] Advantages of oil removal: The removal rate of oil by the composite agent reached 93%, which was better than that of single agent A (88%), possibly due to the adsorption of emulsified oil by activated carbon and the demulsification effect of PAM.

[0046] 2. Impact on subsequent biochemical systems analyze: The composite agent improves biochemical efficiency: the COD and ammonia nitrogen in the biochemical effluent of the experimental group F were reduced by 21.9% and 33.3% respectively compared with the control group A, indicating that the pretreatment removed more inhibitory substances (such as residual phenols) and improved the biodegradability of the wastewater.

[0047] Enhanced sludge activity: SDH activity reflects the metabolic intensity of microorganisms. The activity of group F increased by 31.8% compared with group A, indicating that the compound agent reduced the inhibition of toxic substances on microorganisms and promoted nitrification-denitrification reaction.

[0048] V. Conclusion Necessity of optimizing the ratio of compound medicines: The ratio of polyferric sulfate: activated carbon: non-ionic polyacrylamide = 180:50:1.5 can significantly improve the pollutant removal efficiency, among which: Polyferric sulfate provides flocculation core to remove SS and part of COD; Activated carbon adsorbs residual phenols, oils and small molecular organic matter; Non-ionic polyacrylamide forms tight flocs through the bridging effect of long-chain molecules, accelerating sedimentation.

[0049] Contribution to the overall process: The pretreatment stage creates favorable conditions for subsequent biochemical systems (e.g., reducing phenolic inhibition and SS load); The synergistic effect increases the overall COD removal rate of the entire process to more than 90%, and the ammonia nitrogen removal rate is ≥95%, ensuring that the final effluent meets the standards.

Claims

1. A process for deep treatment of ammonia evaporation wastewater, comprising ammonia evaporation wastewater pretreatment, biochemical treatment, reuse treatment, concentrated water treatment and sludge treatment, characterized in that: In the biochemical treatment stage, the pretreated wastewater enters an aerobic tank for phenol reduction treatment; Then it passes through a two-stage A / O biochemical system; The effluent is then fed into a sedimentation tank and adsorbed with coagulant, and then oxidized by ozone.

2. A process for deep treatment of ammonia distillation wastewater according to claim 1, characterized in that: The adsorption coagulant is polyferric sulfate, activated carbon, nonionic polyacrylamide or a combination thereof.

3. A process for deep treatment of ammonia distillation wastewater according to claim 2, characterized in that: The adsorption coagulant is composed of polyferric sulfate, activated carbon and non-ionic polyacrylamide in a mass ratio of (150-200):(40-70):(1-2); and the adsorption coagulant is added in an amount of 250-650 mg / L per liter of wastewater.

4. A process for deep treatment of ammonia distillation wastewater according to claim 3, characterized in that: The adsorption coagulant is composed of polymerized ferric sulfate, activated carbon and non-ionic polyacrylamide in a mass ratio of 180:50:1.

5.

5. The process according to claim 1, characterized in that The two-stage A / O biochemical system comprises a primary A / O unit and a secondary A / O unit connected in sequence; Primary A / O unit: anoxic tank: dissolved oxygen ≤ 0.5 mg / L, hydraulic retention time 10-14 hours, sludge return ratio 100%-200%; Aerobic tank: dissolved oxygen is 2-4 mg / L, hydraulic retention time is 12-16 hours; Secondary A / O unit: anoxic tank: dissolved oxygen ≤ 0.5 mg / L, hydraulic retention time 8-12 hours, sludge return ratio 50%-100%; Aerobic pool: dissolved oxygen is 2-4 mg / L, hydraulic retention time is 10-14 hours.

6. The process according to claim 1, characterized in that Ammonia evaporation wastewater pretreatment stage: Ammonia evaporation wastewater enters the regulating tank and passes through the oil separator and flotation equipment in sequence to remove heavy oil and emulsified oil, and then adjusts the pH to 6.5-7.

5.

7. The process according to claim 1, characterized in that Reuse treatment stage: The wastewater after biochemical treatment passes through a high-density sedimentation tank to remove hardness, suspended matter and oil, and then passes through a filter, an ultrafiltration membrane system and a reverse osmosis membrane system in sequence. The produced water is reused after meeting the standards.

8. The process according to claim 1, characterized in that Brine treatment stage: The brine section is separated into divalent salts and monovalent salts through the first-level nanofiltration. The nanofiltration water is concentrated by the first-level reverse osmosis and then enters the sodium sulfate and sodium chloride evaporation and crystallization systems respectively to recover sodium sulfate and sodium chloride.

9. The process according to claim 1, characterized in that Sludge treatment stage: The sludge in the sedimentation tank is concentrated and dehydrated, the mud cake is sent to the coal blending system, and the filtrate is returned to the regulating tank.

10. The process for deep treatment of ammonia distillation wastewater according to claim 1, characterized in that: The specific steps include: S1. Preprocessing stage: The ammonia wastewater enters the regulating tank and passes through the oil separator and flotation equipment in turn to remove heavy oil and emulsified oil, and then adjusts the pH to 7.0; S2. Biochemical treatment stage: The wastewater enters a high-load aerobic tank for phenol reduction treatment; Then, a two-stage A / O biochemical system is used to remove COD and ammonia nitrogen; The effluent is then fed through a sedimentation tank and adsorbed with coagulant; The effluent from the sedimentation tank is then catalytically oxidized by ozone to further reduce COD; The two-stage A / O biochemical system comprises a primary A / O unit and a secondary A / O unit connected in sequence; Primary A / O unit: anoxic tank: dissolved oxygen ≤ 0.5 mg / L, hydraulic retention time 12 hours, sludge return ratio 150%; Aerobic tank: dissolved oxygen is 4 mg / L, hydraulic retention time is 14 hours; Secondary A / O unit: anoxic tank: dissolved oxygen ≤ 0.5 mg / L, hydraulic retention time of 10 hours, sludge return ratio of 75%; aerobic tank: dissolved oxygen 3 mg / L, hydraulic retention time of 12 hours; The adsorption coagulant is polyferric sulfate, activated carbon and non-ionic polyacrylamide in a mass ratio of 180:50:1.5, and the adsorption coagulant is added in an amount of 500 mg / L; S3. Recycling and processing stage: The reuse treatment stage includes high-density sedimentation tanks, filters, ultrafiltration membrane systems and reverse osmosis membrane systems; After biochemical treatment, the wastewater is passed through a high-density sedimentation tank to remove hardness, suspended solids and oil, and then passes through a filter, ultrafiltration system and reverse osmosis membrane system in sequence. The produced water is reused after meeting the standards. S4. Brine treatment stage: The concentrated water section is separated into divalent salts and monovalent salts through the first-stage nanofiltration. The nanofiltration water is concentrated by the first-stage reverse osmosis and then enters the sodium sulfate and sodium chloride evaporation and crystallization systems respectively to recover sodium sulfate and sodium chloride; S5. Sludge treatment stage: The sludge in the sedimentation tank is concentrated and dehydrated, the mud cake is sent to the coal blending system, and the filtrate is returned to the regulating tank.

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