WO2024060693A1 - 一种煤化工废水处理方法及系统 - Google Patents

一种煤化工废水处理方法及系统 Download PDF

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WO2024060693A1
WO2024060693A1 PCT/CN2023/099111 CN2023099111W WO2024060693A1 WO 2024060693 A1 WO2024060693 A1 WO 2024060693A1 CN 2023099111 W CN2023099111 W CN 2023099111W WO 2024060693 A1 WO2024060693 A1 WO 2024060693A1
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treatment
tower
wastewater
tank
temperature
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PCT/CN2023/099111
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English (en)
French (fr)
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王勇
丁泰坤
刘宁
姬锐
孙江江
郑小霞
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陕西煤业化工集团神木天元化工有限公司
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Publication of WO2024060693A1 publication Critical patent/WO2024060693A1/zh

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
    • C01C1/00—Ammonia; Compounds thereof
    • C01C1/02—Preparation, purification or separation of ammonia
    • C01C1/10—Separation of ammonia from ammonia liquors, e.g. gas liquors
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D3/00—Halides of sodium, potassium or alkali metals in general
    • C01D3/04—Chlorides
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D3/00—Halides of sodium, potassium or alkali metals in general
    • C01D3/14—Purification
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D5/00—Sulfates or sulfites of sodium, potassium or alkali metals in general
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D5/00—Sulfates or sulfites of sodium, potassium or alkali metals in general
    • C01D5/16—Purification
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/02—Treatment of water, waste water, or sewage by heating
    • C02F1/04—Treatment of water, waste water, or sewage by heating by distillation or evaporation
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/26—Treatment of water, waste water, or sewage by extraction
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/40—Devices for separating or removing fatty or oily substances or similar floating material
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
    • C02F1/56—Macromolecular compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/66—Treatment of water, waste water, or sewage by neutralisation; pH adjustment
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00—Biological treatment of water, waste water, or sewage
    • C02F3/30—Aerobic and anaerobic processes
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00—Biological treatment of water, waste water, or sewage
    • C02F3/34—Biological treatment of water, waste water, or sewage characterised by the microorganisms used
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F9/00—Multistage treatment of water, waste water or sewage
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/10—Inorganic compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/10—Inorganic compounds
    • C02F2101/16—Nitrogen compounds, e.g. ammonia
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/30—Organic compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/30—Organic compounds
    • C02F2101/34—Organic compounds containing oxygen

Definitions

  • This application belongs to the field of wastewater treatment technology, and specifically relates to a coal chemical wastewater treatment method and system.
  • the composition of coal chemical wastewater is complex, containing a large amount of solid suspended particles, a variety of phenolic compounds, polycyclic aromatic compounds, nitrogen/oxygen/sulfur-containing heterocyclic compounds and other refractory pollutants, as well as toxic and harmful organic pollutants such as oil.
  • inorganic pollutants such as ammonia nitrogen and sulfide
  • the COD and chroma of the wastewater are very high, making it an industrial wastewater that is difficult to treat.
  • the existing technology has proposed some treatment processes for coal chemical wastewater. Due to the high concentration of phenols and ammonia nitrogen compounds in coal chemical wastewater, it is not suitable for direct biochemical treatment, and it is difficult to achieve discharge by simply using physical or chemical methods. Standards require comprehensive consideration of different treatment methods. Therefore, the existing coal chemical wastewater treatment process is mainly composed of a combination of physical and chemical processes, that is, high-concentration phenolic ammonia wastewater is first pretreated, followed by oil removal and deacidification. Deamination, dephenolization and other steps are carried out to reduce the oil and phenolic ammonia content in the wastewater, and then further biochemical treatment is carried out to make the water meet discharge or reuse standards.
  • the residual amount of acid gas is too high, and the residual amount of acid gas is too high will reduce the dephenolization efficiency in the later stage;
  • the separation of ammonia and phenol is not complete, resulting in high phenol and acid gas content in the ammonia product , increasing the load of subsequent ammonia refining;
  • the dephenolization efficiency is low, resulting in the wastewater still containing higher concentrations of phenolic compounds, increasing This reduces the load of subsequent biochemical treatment;
  • the wastewater contains a certain amount of suspended solids, equipment such as heat exchangers is seriously scaled, and the heat exchanger has poor heat transfer effect, resulting in high energy consumption in sewage treatment, and it must be carried out after deamination.
  • the extracted wastewater has a high temperature and still needs to be cooled by a cooler, which consumes a large amount of circulating cooling water and consumes a lot of energy.
  • the technical problem to be solved by the present application is to overcome the defects of the existing coal chemical wastewater treatment process, such as incomplete deacidification, poor separation of ammonia and phenol during deamination, low dephenolization efficiency and high energy consumption.
  • this application provides a method for treating coal chemical wastewater, which includes the process of sequentially pretreating, biochemical treatment, advanced treatment, and evaporation crystallization of coal chemical wastewater; the pretreatment process includes the following steps:
  • coal chemical wastewater treatment method is selected from any one of the following characteristics:
  • step S13 Use the acid liquid obtained by deacidification in step S13 as a pH regulator for step S12 and/or step S15.
  • Step S14 also includes a desolventization step: first perform a desolventization treatment on the deacidified wastewater, and then perform a deamination treatment on the desolventized wastewater.
  • step S12 Purify the first extract obtained by the first-stage extraction and dephenolization in step S12 and/or the second extract obtained by the second-stage extraction and dephenolization in step S15 to extract phenol, to obtain crude phenol.
  • step D Reuse at least one of the first solvent obtained from the first desolvation in step S14, the second solvent obtained from the second desolvation in step S16, and the third solvent obtained from the refining and phenol extraction step as an extraction agent to the step. S12 and/or step S15.
  • the biochemical treatment process includes the following steps:
  • the wastewater after completing the pretreatment process is sequentially subjected to anaerobic bacterial degradation treatment and nitrogen and carbon removal treatment.
  • a secondary oil removal treatment is also included before performing the anaerobic bacterial degradation treatment.
  • a mud-water separation step is further included after the denitrification and carbon removal treatment.
  • the advanced treatment process includes the following steps: sequentially subjecting the wastewater after completing the biochemical treatment process to coagulation sedimentation treatment and reverse osmosis membrane treatment.
  • the evaporation and crystallization process includes the following steps: heating the wastewater after completing the advanced treatment process, and crystallizing and separating slag salts to obtain purified water.
  • the second sludge obtained by the coagulation sedimentation treatment and/or the first sludge obtained by the mud-water separation step is dehydrated, and the resulting aqueous phase is mixed with the wastewater after the secondary oil removal treatment.
  • this application also provides a coal chemical industry wastewater treatment system, including a pretreatment unit, a biochemical treatment unit, an advanced treatment unit and an evaporation crystallization unit connected in sequence; characterized in that the pretreatment unit includes a pretreatment unit connected in sequence. It is equipped with a primary oil removal tank, a first regulating tower, a first-level extraction tower, a deacidification tower, a second regulating tower, a deamination tower, a third regulating tower, a second-level extraction tower and a second desolventization tower;
  • the primary oil removal tank is used for primary oil removal treatment of coal chemical wastewater
  • the first regulating tower is used to adjust the pH value of the wastewater after primary oil removal to ⁇ 7;
  • the first-level extraction tower is used to perform first-level extraction and dephenolization treatment of wastewater with a pH value ⁇ 7 after primary oil removal;
  • the deacidification tower is used to deacidify the wastewater after the first-level extraction and dephenolization;
  • the second regulating tower is used to adjust the pH value of the deacidified wastewater to ⁇ 8;
  • the deamination tower is used to deaminate wastewater with a pH value ⁇ 8;
  • the third regulating tower is used to adjust the pH value of the deamination wastewater to ⁇ 7;
  • the two-stage extraction tower is used to perform a two-stage extraction and dephenolization treatment on wastewater with a pH value ⁇ 7 after deamination;
  • the second desolventization tower is used for secondary desolventization treatment of wastewater after dephenolization in the secondary extraction.
  • coal chemical industry wastewater treatment system is selected from any one of the following characteristics:
  • the acid outlet of the deacidification tower is connected to the acid inlet of the first regulating tower and/or the second regulating tower.
  • a first desolventization tower is also provided between the deacidification tower and the second regulating tower for performing a primary desolventization treatment on the deacidified wastewater.
  • the pretreatment unit also includes an extract tank, a phenol tower and a crude phenol tank that are connected in sequence.
  • the inlet of the extract tank is connected to the extract of the first-level extraction tower and/or the second-level extraction tower.
  • the outlets are connected;
  • the phenol tower is used to refine and extract phenol from the first extract obtained from the first-stage extraction and/or the second extract obtained from the second-stage extraction and to remove phenol;
  • the crude phenol tank is used for To accommodate the crude phenol produced in the phenol tower.
  • the pretreatment unit also includes a solvent circulation tank, the inlet of which is connected to the solvent outlet of at least one of the first desolventizing tower, the second desolventizing tower, and the phenol tower, and the outlet of which is connected to the extractant inlet of the primary extraction tower and/or the secondary extraction tower.
  • the biochemical treatment unit includes:
  • a degradation tank is used to perform anaerobic bacterial degradation treatment on the wastewater flowing out from the pretreatment unit; and a biochemical reaction tank is used to perform denitrification and carbon removal treatment on the wastewater after the anaerobic bacterial degradation treatment.
  • the biochemical treatment unit further includes a secondary oil removal tank for secondary oil removal treatment of the wastewater flowing out from the second desolventizer tower.
  • the biochemical treatment unit further includes a primary sedimentation tank for separating mud and water from the wastewater after denitrification and carbon removal.
  • the mud outlet of the primary sedimentation tank is connected to the inlet of the degradation tank for reusing the first sludge portion obtained in the mud-water separation step into the anaerobic bacteria degradation treatment step.
  • the advanced treatment unit includes: a coagulation sedimentation tank for coagulation and sedimentation treatment of wastewater flowing out from the biochemical treatment unit; and a membrane filtration device for coagulation and sedimentation treatment of the wastewater. Wastewater undergoes reverse osmosis membrane treatment.
  • the advanced treatment unit further includes a sludge concentration tank and a sludge dehydration device connected in sequence, and the sludge outlet of the coagulation sedimentation tank and/or the sludge outlet of the primary sedimentation tank is connected with the sludge outlet.
  • the inlet of the mud concentration tank is connected, and the water outlet of the sludge dehydration device is connected with the water inlet of the degradation tank.
  • the evaporation and crystallization unit includes an MVR evaporation and crystallization device, used to heat the wastewater flowing out of the advanced treatment unit, crystallize and separate slag salts, and obtain purified water.
  • MVR evaporation and crystallization device used to heat the wastewater flowing out of the advanced treatment unit, crystallize and separate slag salts, and obtain purified water.
  • the coal chemical wastewater treatment system further includes: a raw material storage tank, the inlet of the raw material storage tank is connected to the outlet of the primary oil removal tank, and the outlet of the raw material storage tank is connected to the first regulating tower.
  • coal chemical wastewater treatment system is selected from any one of the following features:
  • the liquid level of the tower kettle of the first regulating tower is 1.3 ⁇ 2m, the pressure at the bottom of the tower is 50 ⁇ 200KPa, and the pressure at the top of the tower is 370 ⁇ 410KPa.
  • the top temperature of the deacidification tower is 35-50°C, and the pressure is 0.2-0.6MPa; the bottom temperature is 130-145°C, and the pressure is 0.22-0.62MPa; the reflux ratio is 1-7, and the number of plates is 25 ⁇ 45.
  • the top temperature of the deamination tower is 135-150°C, and the pressure is 0.3-0.7MPa; the bottom temperature is 148-160°C, and the pressure is 0.33-0.73MPa; the reflux ratio is 2-9, and the number of plates It is 35 ⁇ 45.
  • the operating temperature of the first-stage extraction tower is 25-65°C
  • the pressure is 90-350KPa
  • the solvent ratio is 2:1-9:1
  • the number of plates is 70-90;
  • the operating temperature of the secondary extraction tower is 25-65°C
  • the pressure is 90-350KPa
  • the solvent ratio is 2:1-9:1
  • the number of plates is 70-90.
  • the tower top temperature of the secondary desolventization tower is 88-105°C, and the tower bottom temperature is 95-110°C.
  • the top temperature of the phenol tower is 95-105°C, and the tower bottom temperature is 205-215°C.
  • the temperature of the secondary oil removal tank is 40-60°C, the dissolved gas pressure is 0.4-0.6Mpa, and the gas-water ratio is 30-50%.
  • the hydraulic retention time of the degradation tank is 15 to 20 hours, the pH is 5 to 7, the temperature is maintained at 21 to 32°C, and the dissolved oxygen content is 0 to 0.5 mg/L.
  • the biochemical reaction pool includes a primary aerobic pool, an anaerobic pool and a secondary aerobic pool connected in sequence.
  • the inlet of the primary aerobic pool is connected to the outlet of the degradation pool, and the secondary aerobic pool is connected in sequence.
  • the oxygen tank is connected to the inlet of the primary sedimentation tank; the temperature of the anaerobic tank is 35 ⁇ 38°C, the dissolved oxygen content is controlled at 0 ⁇ 0.5mg/L, the pH value is 6.5 ⁇ 7.2, and the hydraulic retention time is 1.5 ⁇ 2h; the parameters of the first-level aerobic pool and the second-level aerobic pool are that the temperature is 29-37°C, the dissolved oxygen content is controlled at 2-8mg/L, the hydraulic retention time is 7-9h, and the pH value is 8.0 ⁇ 8.5.
  • the pH of the primary sedimentation tank is 6 to 9, the sedimentation treatment time is 3 to 5 hours, and the sludge return ratio is 50% to 200%.
  • the water temperature of the coagulation sedimentation tank is 20 to 30°C, the settling time is 4 to 6 hours, and the sludge return ratio is 50% to 100%.
  • the operating pressure of the membrane filtration device is 0.05Mpa.
  • the temperature of the first evaporation and concentration of the MVR evaporation and crystallization device is 50-150°C, and the crystallization temperature is 50-100°C; during the second evaporation and crystallization, the temperature of the evaporation and concentration is 50-150°C, and the crystallization temperature is 30 ⁇ 50°C.
  • the coal chemical wastewater treatment method provided in the embodiment of the present application comprises a process of pretreatment, biochemical treatment, deep treatment and evaporation crystallization of the coal chemical wastewater in sequence, wherein the pretreatment process comprises a primary deoiling treatment of the coal chemical wastewater, adjusting the pH value of the wastewater after the primary deoiling to ⁇ 7, then performing a primary extraction dephenolization and deacidification treatment, adjusting the pH value of the wastewater after deacidification to ⁇ 8 and then performing a deamination treatment, and then adjusting the pH value of the wastewater after deamination to ⁇ 7, and then performing a secondary extraction dephenolization and a secondary desolventization treatment.
  • the pretreatment process comprises a primary deoiling treatment of the coal chemical wastewater, adjusting the pH value of the wastewater after the primary deoiling to ⁇ 7, then performing a primary extraction dephenolization and deacidification treatment, adjusting the pH value of the wastewater after deacidification to ⁇ 8 and then performing a deamination treatment, and then
  • the present application reduces the pH value of the wastewater to below 7 before deacidification and deamination, and then performs a primary dephenolization treatment, which can greatly improve the dephenolization efficiency, remove most of the phenolic substances in the wastewater, avoid incomplete separation of ammonia and phenol during deamination, resulting in high phenol and acid gas content in the ammonia product, and increase the load of subsequent ammonia refining; and the present application also adjusts the pH value of the wastewater to below 7 after deamination for secondary dephenolization treatment to completely remove the phenolic substances in the wastewater, greatly reducing the load of subsequent biochemical treatment.
  • the present application adjusts the pH value of the wastewater to ⁇ 8 after deacidification, and then performs deamination treatment, which is beneficial to improving the deamination efficiency.
  • coal chemical wastewater treatment method provided in the embodiment of this application adopts the patented technology "SH-A energy-saving enhanced biological denitrification and carbon removal process" disclosed in CN 1778725A in the biochemical treatment process to improve the treatment of organic matter and carbon dioxide in the wastewater. Ammonia nitrogen removal rate.
  • the wastewater is first subjected to coagulation and sedimentation treatment in the advanced treatment process, and the coagulation agent is used to absorb the unremoved organic matter and suspended matter in the wastewater to form larger particles. Precipitate through gravity to achieve the purpose of further removing organic matter and suspended matter. Firstly, it avoids clogging of subsequent membrane filtration devices. Secondly, it avoids severe scaling of heat exchangers and other equipment, resulting in poor heat exchange effect and high energy consumption in wastewater treatment. .
  • the coal chemical wastewater treatment method of the present application can also be used as a top spray of the tail gas absorption tower installed at the gas vent end of each device in the pretreatment stage. Washing liquid, ammonia washing at the top of the first regulating tower, reflux at the top of the deacidification tower, reflux in the primary desolventizer tower, and reflux in the secondary desolventizer tower itself realize multi-stage recycling in the wastewater treatment process to avoid consuming a large amount of water. Circulating cooling water reduces overall process energy consumption.
  • the crude phenol, crude ammonia, and acid gas produced by the coal chemical wastewater treatment method of this application can be sold as products after being processed by the refined phenol device, ammonia refining device, and sulfur device respectively, realizing efficient and comprehensive wastewater resources. use.
  • the coal chemical wastewater treatment system comprises a pretreatment unit, a biochemical treatment unit, a deep treatment unit and an evaporation crystallization unit which are connected in sequence
  • the pretreatment unit comprises a primary oil removal tank, a first adjusting tower, a primary extraction tower, a deacidification tower, a second adjusting tower, a deamination tower, a third adjusting tower, a secondary extraction tower and a second desolventizing tower which are connected in sequence, and is used to perform a primary oil removal treatment on the coal chemical wastewater, adjust the pH value of the wastewater after the primary oil removal to ⁇ 7, and then perform a primary extraction dephenolization and deacidification treatment, adjust the pH value of the wastewater after deacidification to ⁇ 8 and then perform deamination treatment, and then adjust the pH value of the wastewater after deamination to ⁇ 7, and then perform secondary extraction dephenolization and secondary desolventizing treatment.
  • the present application uses the first regulating tower to reduce the pH value of the wastewater to below 7 before deacidification and deamination, and then performs a primary dephenolization treatment, which can greatly improve the dephenolization efficiency, remove the vast majority of phenolic substances in the wastewater, and avoid incomplete separation of ammonia and phenol during deamination, resulting in high phenol and acid gas content in the ammonia product, increasing the load of subsequent ammonia refining; and the present application also uses the third regulating tower to adjust the pH value of the wastewater to below 7 again after deamination for secondary dephenolization treatment, so as to completely remove phenolic substances in the wastewater, greatly reducing the load of subsequent biochemical treatment.
  • the present application uses the second regulating tower to adjust the pH value of the wastewater to ⁇ 8 after deacidification, and then performs deamination treatment, which is conducive to improving the deamination efficiency.
  • the coal chemical wastewater treatment system adopts a primary oil removal tank with a steel concrete structure connected in series at one or more stages in the pretreatment unit.
  • the oil removal tank has higher compressive strength than the ordinary oil removal tank and can effectively remove light oil, heavy oil and part of the oil residue in the wastewater without introducing any solvent.
  • a composite filler is installed in the degradation tank of the biochemical treatment unit, and a free swinging bracket is used to stand the filler upright in the water body by relying on the buoyancy of the float in the water, and there is a certain amplitude of swing.
  • a rotary water distributor is used for water inlet, and a perforated pipe is provided at the bottom of the tank to achieve uniform water distribution.
  • the anaerobic bacteria in the filler are used to open the ring and break the chain of large molecular and difficult-to-degrade organic matter in the wastewater into small molecular and easily biodegradable organic matter, thereby improving the degradation efficiency.
  • the coal chemical wastewater treatment system provided in the embodiment of the present application adopts a multi-layer stacked disc vibrating membrane high concentration technology equipment in the deep treatment unit, and the concentrated water produced adopts advanced MVR (mechanical vapor recompression) plus multiphase flow evaporation crystallization technology, ultimately achieving the purpose of fully reusing the wastewater and realizing zero emissions.
  • MVR mechanical vapor recompression
  • FIG. 1 is a schematic structural diagram of the coal chemical wastewater treatment system provided in Embodiment 1 of the present application;
  • the reference symbols are as follows: 1-primary oil removal tank; 2-raw material storage tank; 3-first regulating tower; 4-first-level extraction tower; 5-deacidification tower; 6-phenol tower; 7 first desolventization tower ; 8-Second regulating tower, deamination tower; 9-Third regulating tower, secondary extraction tower; 10-Second desolventizing tower; 11-Oil pool; 12-Crude phenol tank; 13-Solvent circulation tank; 14 -Extract tank; 15-secondary oil removal tank; 16-degradation tank; 17-biochemical reaction tank; 18-primary sedimentation tank; 19-coagulation sedimentation tank; 20-membrane filtration device; 21-MVR evaporation crystallization device; 22-Scum collection tank; 23-Sludge concentration tank; 24-Sludge dehydration device;
  • FIG. 2 is a schematic diagram of the specific structure of the combined filler of the coal chemical wastewater treatment system provided in Embodiment 1 of the present application;
  • Figure 3 is a schematic diagram of the combined packing of the coal chemical wastewater treatment system provided in Embodiment 1 of the present application.
  • the coal chemical wastewater treatment system provided in this embodiment includes: a pretreatment unit, a biochemical treatment unit, an advanced treatment unit and an evaporation crystallization unit connected in sequence;
  • the pretreatment unit includes a primary oil removal tank 1, a first regulating tower 3, a first-level extraction tower 4, a deacidification tower 5, a phenol tower 6, a second regulating tower, a deamination tower 8, and a third regulating tower which are connected in sequence.
  • the primary oil removal tank 1 is used for primary oil removal treatment of coal chemical wastewater; the first regulating tower 3 is used for adjusting the pH value of the wastewater after primary oil removal to ⁇ 7; the primary extraction tower 4 is used for primary extraction dephenolization treatment of the wastewater with a pH value of ⁇ 7 after primary oil removal; the deacidification tower 5 is used for deacidification treatment of the wastewater after primary extraction dephenolization; the second regulating tower is used for adjusting the pH value of the wastewater after deacidification to ⁇ 8; the deammonification tower 8 is used for deammonification treatment of the wastewater with a pH value of ⁇ 8; the third regulating tower is used for adjusting the pH value of the wastewater after deammonification to ⁇ 7; the secondary extraction tower 9 is used for deammonification treatment of the wastewater with a pH value of ⁇ 7 after deammonification
  • the wastewater is subjected to secondary extraction and dephenolization treatment; the second desolventizing tower 10 is used to perform secondary desolventizing treatment on the wastewater after the secondary extraction and de
  • the biochemical treatment unit includes a secondary oil removal tank 15, a degradation tank 16, a biochemical reaction tank 17, a primary sedimentation tank 18, and a secondary oil removal tank 15 connected in sequence, which are used to secondary process the wastewater flowing out from the second desolventizer tower 10. Secondary oil removal treatment;
  • the degradation tank 16 is used for anaerobic bacterial degradation of the wastewater flowing out from the pretreatment unit; and the biochemical reaction tank 17 is used for denitrification and carbon removal of the wastewater after anaerobic bacterial degradation;
  • the primary sedimentation tank 18 is used to separate mud and water from the wastewater after denitrification and carbon removal; the mud outlet of the primary sedimentation tank 18 is connected to the inlet of the degradation tank 16, and is used to return the first sludge part obtained in the mud and water separation step. used in the anaerobic bacterial degradation treatment step.
  • the advanced treatment unit includes a coagulation sedimentation tank 19, a membrane filtration device 20, a sludge concentration tank 23 and a sludge dehydration device 24 connected in sequence.
  • the coagulation sedimentation tank 19 is used for coagulation and sedimentation treatment of the wastewater flowing out from the biochemical treatment unit; and the membrane filtration device 20 is used for reverse osmosis membrane treatment of the wastewater after coagulation and sedimentation treatment;
  • the sludge concentration tank 23 and the sludge dehydration device 24 are connected with the sludge outlet of the coagulation sedimentation tank 19 and the primary sedimentation tank 18 with the inlet of the sludge concentration tank 23.
  • the outlet of the sludge dehydration device 24 is connected with the degradation outlet.
  • the water inlet of pool 16 is connected.
  • the evaporation and crystallization unit includes an MVR evaporation and crystallization device 21, which is used to heat the wastewater flowing out of the advanced treatment unit, crystallize and separate the slag salt, and obtain purified water;
  • the coal chemical wastewater treatment system may also include a raw material storage tank 2;
  • Raw material storage tank 2 the inlet of the raw material storage tank 2 is connected to the outlet of the primary oil removal pool 1, and the outlet of the raw material storage tank 2 is connected to the inlet of the first regulating tower 3;
  • the coal chemical wastewater treatment system may also include an oil pool 11, which is used to recover the oil waste once removed by the primary oil removal pool 1;
  • the coal chemical wastewater treatment system may also include a scum collection tank 22 , and the inlet of the scum collection tank 22 is connected to the slag outlet of the secondary oil removal tank 15 .
  • reactor/tower/reaction pool/device parameters are:
  • the liquid level of the tower kettle of the first regulating tower 3 is 1.3 ⁇ 2m, the pressure at the bottom of the tower is 50 ⁇ 200KPa, and the pressure at the top of the tower is 370 ⁇ 410KPa;
  • the top temperature of deacidification tower 5 is 35-50°C, and the pressure is 0.2-0.6MPa; the bottom temperature is 130-145°C, and the pressure is 0.22-0.62MPa; the reflux ratio is 1-7, and the number of plates is 25-45 ;
  • the top temperature of the deamination tower 8 is 135-150°C, and the pressure is 0.3-0.7MPa; the bottom temperature is 148-160°C, and the pressure is 0.33-0.73MPa; the reflux ratio is 2-9, and the number of plates is 35-45;
  • the operating temperature of the primary extraction tower 4 is 25-65°C, the pressure is 90-350KPa, the solvent ratio is 2:1-9:1, and the number of plates is 70-90;
  • the operating temperature of the secondary extraction tower 9 is 25-65°C, the pressure is 90-350KPa, the solvent ratio is 2:1-9:1, and the number of plates is 70-90;
  • the tower top temperature of the secondary desolventization tower 10 is 88-105°C, and the tower bottom temperature is 95-110°C;
  • the top temperature of phenol tower 6 is 95 ⁇ 105°C, and the tower kettle temperature is 205 ⁇ 215°C;
  • the temperature of the secondary degreasing tank 15 is 40-60°C, the dissolved gas pressure is 0.4-0.6Mpa, and the gas-water ratio is 30-50%;
  • the hydraulic retention time of the degradation tank 16 is (HRT) 15 to 20 hours, the pH is 5 to 7, the temperature is maintained at 21 to 32°C, and the dissolved oxygen content is 0 to 0.5 mg/L;
  • the biochemical reaction pool 17 includes a primary aerobic pool, an anaerobic pool and a secondary aerobic pool connected in sequence.
  • the inlet of the primary aerobic pool is connected to the outlet of the degradation pool 16.
  • the secondary aerobic pool It is connected to the inlet of the primary sedimentation tank 18;
  • the temperature of the anaerobic tank is 35 ⁇ 38°C, the dissolved oxygen content is controlled at 0 ⁇ 0.5mg/L, the pH value is 6.5 ⁇ 7.2, and the hydraulic retention time is 1.5 ⁇ 2h ;
  • the parameters of the first-level aerobic pool and the second-level aerobic pool are that the temperature is 29 ⁇ 37°C, the dissolved oxygen content is controlled at 2 ⁇ 8mg/L, the hydraulic retention time is 7 ⁇ 9h, and the pH value is 8.0 ⁇ 8.5;;
  • the pH of the primary sedimentation tank 18 is 6 to 9, the sedimentation treatment time is 3 to 5 hours, and the sludge return ratio is 50% to 200%; the water temperature of the coagulation sedimentation tank 19 is 20 to 30°C, and the sedimentation time is 4 to 6 hours. Mud return ratio is 50% to 100%;
  • the operating pressure of the membrane filtration device 20 is 0.05Mpa;
  • the first evaporation and concentration temperature of the MVR evaporation and crystallization device 21 is 50-150°C, and the crystallization temperature is 50-100°C; during the second evaporation and crystallization, the evaporation and concentration temperature is 50-150°C, and the crystallization temperature is 30-50°C. .
  • the specific combination of filler is: its structure is to change the plastic disc buckle into a double-circle large plastic ring, and press aldehyde fiber or polyester silk on the ring of the ring to make the fiber bundles evenly distributed; the inner ring is a snowflake-shaped plastic branch , can not only hang film, but also effectively cut bubbles, improving the oxygen transfer rate and utilization rate.
  • the specific structure of the combined filler is shown in Figures 2 to 3.
  • the water-vapor biofilm can be fully exchanged, and the organic matter in the water can be processed.
  • Combined packing is an ideal choice of packing in the case of strong aeration and turbulent water flow.
  • the wastewater After the wastewater enters the primary oil removal tank and removes the light oil, heavy oil and part of the oil residue in the wastewater, it is sent to the upper part of the first regulating tower, and the light and heavy oil are recovered as products.
  • the raw sewage containing hydrogen sulfide acidic gas from the deacidification tower is introduced into the lower part of the first regulating tower. After full contact and mass transfer with the hydrogen sulfide-containing gas, the pH value drops below 7, and is transported from the bottom of the tower through the first regulating tower still liquid pump.
  • the gas containing hydrogen sulfide in the first regulating tower is extracted from the top of the tower after being washed with the still liquid from the second desolventizing tower and enters the sulfur device.
  • the sewage from the first regulating tower still liquid enters the top of the first-level extraction tower, and the extraction agent methyl tert-amyl ether from the solvent circulation tank enters at the bottom.
  • the phenolic oil in the wastewater is extracted into the extraction phase, and the extraction phase is
  • the phase is discharged from the top of the tower to the phenol recovery tower, the extractant is fed into the extract tank, and the waste water is discharged from the bottom of the tower to the deacidification tower.
  • the deacidification tower is used to remove acidic gases from the wastewater after removing phenolic oil.
  • the gas phase at the top of the tower is condensed and goes to the first regulating tower.
  • the tower still liquid enters the first desolventization tower.
  • Potassium oxide adjusts the pH to greater than 8 and then enters the deamination tower.
  • the ammonia in the wastewater is removed in the deamination tower.
  • the ammonia gas containing 75% of the water vapor in the tower top gas phase enters the ammonia refining system.
  • the tower still liquid is mixed with the sulfuric acid in the wastewater adjustment tank to adjust the pH to below 7 and then enters the secondary extraction tower. After the sewage fully contacts the extraction agent in the secondary extraction tower, most of the remaining oils and phenols are extracted into the solvent.
  • the extraction phase enters the extract tank, and the water phase enters the second desolventization tower.
  • the second desolventizing tower still liquid is removed from the tail gas absorption tower top for spray washing, the first regulating tower top is washed with ammonia, the deacidification tower top is used as reflux, the first desolventizing tower is used as reflux, and the second desolventizing tower itself is used.
  • the extract extracted from the top of the second desolventizer tower and the first desolventizer tower all enters the extract tank and enters the phenol tower after separation.
  • a dissolved air secondary oil removal tank is set up in the front stage of the process to ensure the water inlet requirements of the biochemical treatment system.
  • the sewage After the secondary degreasing by dissolved air, the sewage enters the degradation tank.
  • Anaerobic biological bacteria make the macromolecules and difficult-to-degrade organic matter in the water open and break chains, and transform into small molecules and easily biodegradable organic matter.
  • a combined filler is installed in the degradation tank.
  • the filler is made of The bracket swings freely, and a rotating water distributor is used for water inlet.
  • the patented technology "SH-A energy-saving enhanced biological denitrification and carbon removal process” is used to sequentially perform aerobic-anaerobic-aerobic treatment to remove organic matter and ammonia nitrogen from the wastewater of the degradation reaction tank.
  • the effluent from the biochemical reaction tank enters the primary sedimentation tank to separate the mud-water mixture.
  • the separated sludge is discharged to the sludge storage tank through static pressure discharge, and then sent to the sludge concentration tank for treatment.
  • the wastewater enters the coagulation sedimentation tank.
  • the coagulation agent polyacrylamide is added to the mixing reaction tank. After the effluent from the secondary sedimentation tank is fully mixed with the agent, the effluent enters the coagulation sedimentation tank.
  • the coagulation agent added in the tank can absorb the organic matter and suspended matter that have not been removed in the sewage. Combined into larger particles, they settle down through gravity to further remove organic matter and suspended solids. After passing through the mixing sedimentation tank, the effluent enters the high-efficiency anti-clogging reverse osmosis membrane treatment device to obtain dialyzed water and concentrated water, and the dialyzed water is reused.
  • the concentrated water from the reverse osmosis membrane is first sent to the soda-water separator.
  • the steam-water separator and the evaporator form a forced circulation evaporator.
  • the salty wastewater is heated in the evaporator.
  • the gas and liquid are separated in the steam-water separator.
  • the wastewater concentrated to 25% is sent to the crystallization tank for further crystallization and separation.
  • the mother liquor is preheated by the mother liquor. After preheating, it enters the steam-water separator to continue evaporation.
  • the steam generated by evaporation enters the compressor and is compressed, and then enters the evaporator as a heating medium.
  • the condensate water condensed in the evaporator enters the condensate water tank, and enters the mother liquor preheater through the condensate water pump to heat the mother liquor.
  • inert particles of aluminum oxide and polyethylene with a particle density of 1200 to 3000kg/m 3 , a particle size of 0.32 to 3.8mm, and a specific heat of 0.5 to 1.5kJ/kg ⁇ K are added.
  • the PTFE composite particles form a three-phase flow inside the equipment to achieve the purpose of anti-scaling.
  • the operating parameters of the corresponding reactor/tower/reaction tank/device are:
  • the first regulating tower the liquid level in the tower kettle is 1.3m, the pressure at the bottom of the tower is 50Kpa, and the pressure at the top of the tower is 370Kpa;
  • Deacidification tower The top temperature is 35°C, the pressure is 0.2Mpa, the bottom temperature is 130°C, the pressure is 0.22Mpa, the reflux ratio is 1, and the number of plates is 25;
  • Deamination tower Top temperature 135°C, pressure 0.3, bottom temperature 148°C, pressure 0.33, reflux ratio 2, number of plates 35;
  • First-stage extraction tower operating temperature 25°C, pressure 90Kpa, solvent ratio 2:1, number of plates 70;
  • Secondary extraction tower operating temperature 25°C, pressure 90Kpa, solvent ratio 2:1, number of plates 70;
  • the top temperature of the secondary desolventizer tower is 88°C, and the tower bottom temperature is 95°C;
  • Phenol tower The tower top temperature is 95°C, and the tower kettle temperature is 205°C;
  • Degradation tank hydraulic retention time (HRT) 15h, pH 5, temperature maintained at 21°C, dissolved oxygen content 0mg/L;
  • Biochemical reaction pool anaerobic pool: the temperature is 35°C, the dissolved oxygen content is controlled at 0 mg/L, the pH value is 6.5, and the hydraulic retention time is 1.5;
  • the first-level aerobic pool the temperature is 29°C; the dissolved oxygen content is controlled at 2mg/L L, hydraulic retention time is 7h, pH value is 8.0;
  • secondary aerobic pool temperature is 29°C; dissolved oxygen content is controlled at 2mg/L, hydraulic retention time is 7h, pH value is 8.0;
  • Coagulation sedimentation tank water temperature 20°C, settling time 4 hours, sludge return ratio 50%;
  • Membrane filtration device operating pressure 0.05Mpa;
  • MVR evaporation crystallization device the evaporation concentration temperature is 50°C, the crystallization temperature is 50°C, and sodium sulfate crystals are obtained; during secondary evaporation and crystallization, the evaporation concentration temperature is 50°C, and the crystallization temperature is 30°C, to obtain sodium chloride crystals.
  • the extraction agent is methyl isobutyl ketone and the coagulating agent is polyaluminum chloride.
  • reaction kettle/tower/reaction pool/device parameters are:
  • the first regulating tower the liquid level in the tower kettle is 1.7m, the pressure at the bottom of the tower is 130Kpa, and the pressure at the top of the tower is 400Kpa;
  • Deacidification tower Top temperature is 40°C, pressure is 0.4Mpa, bottom temperature is 138°C, pressure is 0.42Mpa, reflux ratio is 5, and number of plates is 30;
  • the top temperature is 140°C, the pressure is 0.4Mpa, the bottom temperature is 155°C, the pressure is 0.53Mpa, the reflux ratio is 5, and the number of plates is 41;
  • Primary extraction tower operating temperature 65°C, pressure 350Kpa, solvent ratio 9:1, plate number 90;
  • Secondary extraction tower operating temperature 65°C, pressure 350Kpa, solvent ratio 9:1, plate number 90;
  • the top temperature of the secondary desolventization tower is 105°C, and the tower bottom temperature is 110°C;
  • the top temperature of the phenol tower is 105°C, and the tower kettle temperature is 215°C;
  • the temperature of the secondary oil removal tank is 60°C, the dissolved air pressure is 0.6Mpa, and the air-to-water ratio is 50%;
  • the hydraulic retention time of the degradation tank is (HRT) 20h, the pH is 7, the temperature is maintained at 32°C, and the dissolved oxygen content is 0.5mg/L;
  • Biochemical reaction pool anaerobic pool: temperature is 38°C, dissolved oxygen content is controlled at 0.5mg/L, pH value is 7.2, hydraulic retention time is 2h; first-level aerobic pool: temperature is 37°C; dissolved oxygen content is controlled at 8mg /L, hydraulic retention time is 9h, pH value is 8.5; secondary aerobic pool: temperature is 37°C; dissolved oxygen content is controlled at 8mg/L, hydraulic retention time is 9h, pH value is 8.5;
  • Coagulation sedimentation tank water temperature is 30°C, settling time is 6 hours, sludge return ratio is 100%;
  • Membrane filtration device operating pressure is 0.05Mpa;
  • MVR evaporation and crystallization device the temperature of the first evaporation and concentration is 150°C, and the crystallization temperature is 100°C, to obtain sodium sulfate crystal; during the second evaporation and crystallization, the temperature of evaporation and concentration is 150°C, and the crystallization temperature is 50°C, to obtain chlorine Sodium crystals.
  • the extraction agent is dimethyl carbonate, and the coagulating agent is polyferric sulfate.
  • reaction kettle/tower/reaction pool/device parameters are:
  • the first regulating tower the liquid level in the tower kettle is 2m, the pressure at the bottom of the tower is 200Kpa, and the pressure at the top of the tower is 410Kpa;
  • Deacidification tower Top temperature 50°C, pressure 0.6Mpa, bottom temperature 145°C, pressure 00.62Mpa, reflux ratio 7, number of plates 45;
  • Deamination tower The temperature at the top of the tower is 150°C, the pressure is 0.7Mpa, the temperature at the bottom is 160°C, the pressure is 0.73Mpa, the reflux ratio is 9, The number of plates is 45;
  • First-stage extraction tower operating temperature 25°C, pressure 90Kpa, solvent ratio 2:1, number of plates 70;
  • Secondary extraction tower operating temperature 35°C, pressure 200Kpa, solvent ratio 5:1, number of plates 80;
  • the tower top temperature is 99°C, and the tower bottom temperature is 100°C;
  • Phenol tower The tower top temperature is 96°C, and the tower kettle temperature is 210°C;
  • Degradation tank hydraulic retention time (HRT) 18h, pH 6, temperature maintained at 27°C, dissolved oxygen content 0.3mg/L;
  • Biochemical reaction pool anaerobic pool: the temperature is 37°C, the dissolved oxygen content is controlled at 0.4mg/L, the pH value is 6.8, and the hydraulic retention time is 2h;
  • the first-level aerobic pool the temperature is 35°C; the dissolved oxygen content is controlled at 4mg /L, hydraulic retention time is 8h, pH value is 8.3;
  • secondary aerobic pool temperature is 37°C; dissolved oxygen content is controlled at 8mg/L, hydraulic retention time is 9h, pH value is 8.5;
  • Coagulation sedimentation tank water temperature 15°C, settling time 5h, sludge return ratio 80%.
  • Membrane filtration device operating pressure is 0.05Mpa;
  • MVR evaporation and crystallization device the temperature of the first evaporation and concentration is 130°C, and the crystallization temperature is 80°C, to obtain sodium sulfate crystal; during the second evaporation and crystallization, the temperature of evaporation and concentration is 120°C, and the crystallization temperature is 45°C, to obtain chlorine Sodium crystals.
  • the pretreatment process includes the following steps:
  • Coal chemical industry wastewater is subjected to primary oil removal treatment, first-level extraction and dephenolization treatment, and deacidification treatment in sequence;
  • the wastewater after deamination is subjected to secondary extraction and dephenolization treatment and secondary desolvation treatment in sequence.
  • the pretreatment process includes the following steps: Coal chemical wastewater is subjected to primary oil removal treatment, deacidification treatment, deamination treatment, extraction and dephenolization treatment and secondary desolvation treatment.
  • Table 4 Water production indicators for evaporation and crystallization treatment

Abstract

本申请属于废水处理技术领域，具体涉及一种煤化工废水处理方法及系统。本申请提供的煤化工废水处理方法，包括依次对煤化工废水进行预处理、生化处理、深度处理以及蒸发结晶的工艺，在预处理工艺中本申请在脱酸脱氨之前先将废水的pH值降低至7以下，之后进行一级脱酚处理，极大地提高脱酚效率，除去废水中绝大多数的酚类物质，避免脱氨时氨与酚分离不彻底，导致氨产品中酚和酸性气体含量高，加大后续氨精制的负荷；本申请还在脱氨之后再次将废水的pH值调节至7以下进行二级脱酚处理，以彻底除去废水中的酚类物质，极大地减轻了后续生化处理的负荷。另外，本申请在脱酸后将废水的pH值调节至≥8，之后再进行脱氨处理，有利于提升脱氨效率。

Description

一种煤化工废水处理方法及系统
相关申请的交叉引用
本申请要求在2022年9月21日提交中国专利局、申请号为202211154511.X、发明名称为“一种煤化工废水处理方法及系统”的中国专利申请的优先权，其全部内容通过引用的方式并入本文中。
技术领域
本申请属于废水处理技术领域，具体涉及一种煤化工废水处理方法及系统。
背景技术
现代煤化工促进了煤炭的清洁和高效化开发利用，但能源生产利用的同时也会产生工业耗水及废水排放的严重问题，并且随着我国节能环保的社会发展意识和趋势的不断加强，国家和企业在污染排放方面的控制力度也随之加大，尤其重视对煤化工废水的处理。
煤化工废水成分复杂，含有大量固体悬浮颗粒、多种酚类化合物、多环芳香族化合物、含氮/氧/硫的杂环化合物等难降解污染物以及油等有毒有害的有机污染物，还有氨氮和硫化物等多种无机污染物，废水COD和色度都很高，属于处理难度较高的工业废水。一旦煤化工废水未经处理或处理不当排入自然环境时，废水中污染物进入受纳水体后极易造成水体富营养化，使水体出现恶臭、变质，严重破坏水源生态系统。
为此，现有技术提出了一些煤化工废水的处理工艺，由于煤化工废水中酚类和氨氮化合物的浓度较高，不适于直接进行生化处理，而单纯地用物理或化学方法又难以达到排放标准，需要对不同的处理方法进行综合考虑，所以现有的煤化工废水处理工艺主要由物化和生化工艺组合而成，即先对高浓度酚氨废水进行预处理，依次包括除油、脱酸脱氨、脱酚等步骤，以降低废水中的油和酚氨含量，再进一步通过生化处理，使水达到排放或回用标准。但从工业装置的实际运行情况来看，上述现有技术存在如下技术问题：(1)脱酸工艺不合理，废水中溶解的离子态的二氧化碳、硫化氢等酸性气体不能经济有效的转化为游离态，酸性气体的残存量过高，过高的酸性气体的残存量会降低后期的脱酚效率；(2)脱氨时，氨、酚的分离不彻底，致使氨产品中酚和酸性气体含量高，加大后续氨精制的负荷；(3)脱酚效率低，致使废水中仍含有较高浓度的酚类化合物，增大 了后续生化处理的负荷；(4)由于废水中含有一定量的悬浮物，致使换热器等设备结垢严重，换热器换热效果差，导致污水处理能耗高，且脱氨后进行萃取的废水温度高，仍需要后续采用冷却器冷却处理，消耗大量的循环冷却水，对能源的消耗很大。
因此，开发一种脱酸脱氨及脱酚效率高且能耗小的煤化工废水处理方法及系统，使得出水达到工业循环水回用标准，最大化实现煤化工废水零污染的排放是十分必要的。
发明内容
鉴于此，本申请要解决的技术问题是克服现有的煤化工废水处理工艺所存在的脱酸不彻底、脱氨时氨与酚的分离度差、脱酚效率低、能源消耗大的缺陷。
本申请的目的是通过以下技术方案实现的：
一方面，本申请提供了一种煤化工废水处理方法，包括依次对煤化工废水进行预处理、生化处理、深度处理以及蒸发结晶的工艺；所述预处理工艺包括以下步骤：
S11、对所述煤化工废水进行一次除油处理；
S12、将一次除油后的废水的pH值调节至≤7，之后进行一级萃取脱酚处理；
S13、对一级萃取脱酚后的废水进行脱酸处理；
S14、将脱酸后的废水的pH值调节至≥8，之后进行脱氨处理；
S15、将脱氨后的废水的pH值调节至≤7，之后进行二级萃取脱酚处理；
S16、对二级萃取脱酚后的废水进行二次脱溶剂处理。
可选地，上述的煤化工废水处理方法，选自如下特征中的任意一个：
A.将步骤S13脱酸得到的酸液作为pH调节剂，用于步骤S12和/或步骤S15。
B.在步骤S14中还包括一次脱溶剂步骤：先对所述脱酸后的废水进行一次脱溶剂处理，再对一次脱溶剂后的废水进行脱氨处理。
C.将步骤S12一级萃取脱酚得到的第一萃取物和/或步骤S15二级萃取脱酚得到的第二萃取物精制提酚，得到粗酚。
D.将步骤S14一次脱溶剂得到的第一溶剂、步骤S16二次脱溶剂得到的第二溶剂、所述精制提酚步骤得到的第三溶剂中的至少一种，作为萃取剂回用至步骤S12和/或步骤S15中。
可选地，所述生化处理工艺包括如下步骤：
对完成所述预处理工艺后的废水依次进行厌氧菌降解处理和脱氮除碳处理。
可选地，在进行所述厌氧菌降解处理之前还包括二次除油处理。
可选地，在进行所述脱氮除碳处理之后还包括泥水分离步骤。
可选地，将所述泥水分离步骤得到的第一污泥部分回用至所述厌氧菌降解处理步骤 中。
可选地，所述深度处理工艺包括如下步骤：对完成所述生化处理工艺后的废水依次进行混凝沉淀处理和反渗透膜处理。
可选地，所述蒸发结晶工艺包括如下步骤：将完成所述深度处理工艺后的废水加热，结晶分离渣盐，即得净化水。
可选地，将所述混凝沉淀处理得到的第二污泥和/或所述泥水分离步骤得到的第一污泥脱水，所得水相与所述二次除油处理后的废水混合。
另一方面，本申请还提供了一种煤化工废水处理系统，包括依次连接设置的预处理单元、生化处理单元、深度处理单元以及蒸发结晶单元；其特征在于，所述预处理单元包括依次连接设置的一次除油池、第一调节塔、一级萃取塔、脱酸塔、第二调节塔、脱氨塔、第三调节塔、二级萃取塔以及第二脱溶剂塔；
其中，所述一次除油池用于对煤化工废水进行一次除油处理；
所述第一调节塔用于将一次除油后的废水的pH值调节至≤7；
所述一级萃取塔用于对一次除油后pH值≤7的废水进行一级萃取脱酚处理；
所述脱酸塔用于对一级萃取脱酚后的废水进行脱酸处理；
所述第二调节塔用于将脱酸后的废水的pH值调节至≥8；
所述脱氨塔用于对pH值≥8的废水进行脱氨处理；
所述第三调节塔用于将脱氨后的废水的pH值调节至≤7；
所述二级萃取塔用于对脱氨后pH值≤7的废水进行二级萃取脱酚处理；
所述第二脱溶剂塔用于对二级萃取脱酚后的废水进行二次脱溶剂处理。
可选地，上述的煤化工废水处理系统，选自如下特征中的任意一个：
A.所述脱酸塔的出酸口与所述第一调节塔和/或所述第二调节塔的进酸口相连。
B.在所述脱酸塔与所述第二调节塔之间还设置有第一脱溶剂塔，用于对所述脱酸后的废水进行一次脱溶剂处理。
C.所述预处理单元还包括依次连接设置的萃取物槽、酚塔以及粗酚槽，所述萃取物槽的进口与所述一级萃取塔和/或所述二级萃取塔的萃取物出口相连；所述酚塔用于对所述一级萃取脱酚得到的第一萃取物和/或所述二级萃取脱酚得到的第二萃取物进行精制提酚；所述粗酚槽用于容纳所述酚塔制得的粗酚。
D.所述预处理单元还包括溶剂循环槽，所述溶剂循环槽的进口与所述第一脱溶剂塔、所述第二脱溶剂塔、所述所述酚塔中的至少一个的溶剂出口相连，所述溶剂循环槽的出口与所述一级萃取塔和/或所述二级萃取塔的萃取剂进口相连。
可选地所述生化处理单元包括：
降解池，用于对从所述预处理单元流出的废水进行厌氧菌降解处理；以及，生化反应池，用于对所述厌氧菌降解处理后的废水进行脱氮除碳处理。
可选地，所述生化处理单元还包括二次除油池，用于对从所述第二脱溶剂塔流出的废水进行二次除油处理。
可选地，所述生化处理单元还包括一次沉淀池，用于对所述脱氮除碳处理后的废水进行泥水分离。
可选地，所述一次沉淀池的出泥口与所述降解池的进口相连，用于将所述泥水分离步骤得到的第一污泥部分回用至所述厌氧菌降解处理步骤中。
可选地，所述深度处理单元包括：混凝沉淀池，用于对从所述生化处理单元流出的废水进行混凝沉淀处理；以及膜过滤装置，用于对所述混凝沉淀处理后的废水进行反渗透膜处理。
可选地，所述深度处理单元还包括依次连接的污泥浓缩池和污泥脱水装置，所述混凝沉淀池的出泥口和/或所述一次沉淀池的出泥口与所述污泥浓缩池的进口连接，所述污泥脱水装置的出水口与所述降解池的进水口相连。
可选地，所述蒸发结晶单元包括MVR蒸发结晶装置，用于将从所述深度处理单元流出的废水加热，结晶分离渣盐，得到净化水。
可选地，所述煤化工废水处理系统还包括：原料储罐，所述原料储罐的进口连接所述一次除油池的出口，所述原料储罐的出口连接所述第一调节塔的进口；浮渣收集池，所述浮渣收集池的进口连接所述二次除油池的出渣口。
可选地，上述的煤化工废水处理系统，选自如下特征中的任意一种：
I.所述第一调节塔的塔釜液位为1.3～2m，塔底压力为50～200KPa，塔顶压力为370～410KPa。
II.所述脱酸塔的塔顶温度为35～50℃、压力为0.2～0.6MPa；塔底温度为130～145℃、压力0.22～0.62MPa；回流比为1～7，塔板数为25～45。
III.所述脱氨塔的塔顶温度为135～150℃、压力为0.3～0.7MPa；塔底温度为148～160℃、压力为0.33～0.73MPa；回流比为2～9，塔板数为35～45。
IV.所述一级萃取塔的操作温度为25～65℃、压力为90～350KPa，溶剂比为2:1～9:1，塔板数为70～90；。
V.所述二级萃取塔的操作温度为25～65℃、压力为90～350KPa，溶剂比为2:1～9:1，塔板数为70～90。
VI.所述二次脱溶剂塔的塔顶温度为88～105℃，塔釜温度为95～110℃。
VII.所述酚塔的塔顶温度95～105℃，塔釜温度为205～215℃。
Ⅷ.所述二次除油池的温度为40～60℃，溶气压力为0.4～0.6Mpa，气水比为30～50％。
Ⅸ.所述降解池的水力停留时间为15～20h，pH为5～7，温度保持在21～32℃，溶解氧含量为0～0.5mg/L。
Ⅹ.所述生化反应池包括依次连接的一级好氧池、厌氧池和二级好氧池，所述一级好氧池的进口与所述降解池出口相连接，所述二级好氧池与所述一次沉淀池的进口相连接；所述厌氧池的温度为35～38℃，溶解氧含量控制在0～0.5mg/L，pH值为6.5～7.2，水力停留时间1.5～2h；所述一级好氧池和所述二级好氧池的参数均为温度为29～37℃，溶解氧含量控制在2～8mg/L，水力停留时间7～9h，pH值为8.0～8.5。
Ⅺ.所述一次沉淀池的pH为6～9，沉淀处理时间3～5h，污泥回流比50％～200％。
Ⅻ.所述混凝沉淀池的水温为20～30℃，沉降时间4～6h，污泥回流比50％～100％。
XIII.所述膜过滤装置的操作压力为0.05Mpa。XIV.所述MVR蒸发结晶装置的第一次蒸发浓缩的温度为50～150℃，结晶温度50～100℃；第二次蒸发结晶时，蒸发浓缩的温度为50～150℃，结晶温度为30～50℃。
与现有技术相比，本申请的技术方案具有如下优点：
1、本申请实施例提供的煤化工废水处理方法，包括依次对煤化工废水进行预处理、生化处理、深度处理以及蒸发结晶的工艺，其中预处理工艺包括对煤化工废水进行一次除油处理，将一次除油后的废水的pH值调节至≤7，之后进行一级萃取脱酚和脱酸处理，将脱酸后的废水的pH值调节至≥8后进行脱氨处理，再将脱氨后的废水的pH值调节至≤7，之后进行二级萃取脱酚和二次脱溶剂处理。本申请在脱酸脱氨之前先将废水的pH值降低至7以下，之后进行一级脱酚处理，这样能够极大地提高脱酚效率，除去废水中绝大多数的酚类物质，避免脱氨时氨与酚的分离不彻底，导致氨产品中酚和酸性气体含量高，加大后续氨精制的负荷；并且本申请还在脱氨之后再次将废水的pH值调节至7以下进行二级脱酚处理，以彻底除去废水中的酚类物质，极大地减轻了后续生化处理的负荷。另外，本申请在脱酸后将废水的pH值调节至≥8，之后再进行脱氨处理，有利于提升脱氨效率。
2、本申请实施例提供的煤化工废水处理方法，在生化处理工艺中采用CN 1778725A所公开的专利技术“SH-A节能型强化生物脱氮除碳工艺”，以提高对废水中的有机物和氨氮的脱除率。
3、本申请实施例提供的煤化工废水处理方法，在深度处理工艺中先将废水进行了混凝沉淀处理，利用混凝药剂吸附废水中未被去除的有机物和悬浮物质以形成较大颗粒，通过重力作用沉淀下来，达到进一步去除有机物和悬浮物的目的，一则避免堵塞后续的膜过滤装置，二则避免换热器等设备因结垢严重而导致换热效果差，废水处理能耗高。
并且，本申请的煤化工废水处理方法除了将二次脱溶剂后的废水送入生化处理工段外，还可以将其用作于设置在预处理阶段各装置气体放空末端的尾气吸收塔顶喷淋洗涤液、第一调节塔顶洗氨、脱酸塔顶作为回流、一次脱溶剂塔作为回流、二次脱溶剂塔本身的回流，实现废水处理过程中的多级循环使用，以避免消耗大量的循环冷却水，降低整体工艺能耗。另外，本申请的煤化工废水处理方法副产的粗酚、粗氨、酸性气分别经精酚装置、氨精制装置、硫磺装置处理后皆可作为产品外售，实现了废水资源的高效、综合利用。
4、本申请实施例提供的煤化工废水处理系统，包括依次连接设置的预处理单元、生化处理单元、深度处理单元以及蒸发结晶单元，其中预处理单元包括依次连接设置的一次除油池、第一调节塔、一级萃取塔、脱酸塔、第二调节塔、脱氨塔、第三调节塔、二级萃取塔以及第二脱溶剂塔，用于对煤化工废水进行一次除油处理，将一次除油后的废水的pH值调节至≤7，之后进行一级萃取脱酚和脱酸处理，将脱酸后的废水的pH值调节至≥8后进行脱氨处理，再将脱氨后的废水的pH值调节至≤7，之后进行二级萃取脱酚和二次脱溶剂处理。本申请在脱酸脱氨之前先利用第一调节塔将废水的pH值降低至7以下，之后进行一级脱酚处理，这样能够极大地提高脱酚效率，除去废水中绝大多数的酚类物质，避免脱氨时氨与酚的分离不彻底，导致氨产品中酚和酸性气体含量高，加大后续氨精制的负荷；并且本申请还在脱氨之后利用第三调节塔再次将废水的pH值调节至7以下进行二级脱酚处理，以彻底除去废水中的酚类物质，极大地减轻了后续生化处理的负荷。另外，本申请在脱酸后利用第二调节塔将废水的pH值调节至≥8，之后再进行脱氨处理，有利于提升脱氨效率。
5、本申请实施例提供的煤化工废水处理系统，在预处理单元中采用具有一级或多级串联的钢砼结构的一次除油池，该除油池比普通除油池耐压强度高，能有效脱除废水中的轻油、重油和部分油渣，而不引入任何溶剂。在生化处理单元的降解池内安装有组合填料，并采用自由摆动支架，依靠浮体在水中的浮力将填料直立在水体之中，且有一定幅度的摆动，同时进水采用旋转布水器，池底设有穿孔管，实现均匀布水，利用填料中的厌氧生物菌使废水中大分子、难降解的有机物开环断链转变为小分子、易生物降解的有机物，提升降解效率。
6、本申请实施例提供的煤化工废水处理系统，在深度处理单元中采用多层叠盘式震动膜高浓缩技术设备，产生的浓缩水采用先进的MVR(机械蒸汽再压缩)加多相流蒸发结晶技术，最终达到废水全部回用的目的，实现零排放。
附图说明
为了更清楚地说明本申请具体实施方式中的技术方案，下面将对具体实施方式描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图是本申请的一些实施方式，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1为本申请实施例1提供的煤化工废水处理系统的结构示意图；
附图标记说明如下：1-一次除油池；2-原料储罐；3-第一调节塔；4-一级萃取塔；5-脱酸塔；6-酚塔；7第一脱溶剂塔；8-第二调节塔、脱氨塔；9-第三调节塔、二级萃取塔；10-第二脱溶剂塔；11-油池；12-粗酚槽；13-溶剂循环槽；14-萃取物槽；15-二次除油池；16-降解池；17-生化反应池；18-一次沉淀池；19-混凝沉淀池；20-膜过滤装置；21-MVR蒸发结晶装置；22-浮渣收集池；23-污泥浓缩池；24-污泥脱水装置；
图2为本申请实施例1提供的煤化工废水处理系统的组合填料具体结构示意图；
图3为本申请实施例1提供的煤化工废水处理系统的组合填料示意图。
具体实施方式
提供下述实施例是为了更好地进一步理解本申请，并不局限于所述最佳实施方式，不对本申请的内容和保护范围构成限制，任何人在本申请的启示下或是将本申请与其他现有技术的特征进行组合而得出的任何与本申请相同或相近似的产品，均落在本申请的保护范围之内。
实施例中未注明具体实验步骤或条件者，按照本领域内的文献所描述的常规实验步骤的操作或条件即可进行。所用试剂或仪器未注明生产厂商者，均为可以通过市购获得的常规试剂产品。
实施例1
本实施例提供的煤化工废水处理系统包括：依次连接设置的预处理单元、生化处理单元、深度处理单元以及蒸发结晶单元；
其中，预处理单元包括依次连接设置的一次除油池1、第一调节塔3、一级萃取塔4、脱酸塔5、酚塔6、第二调节塔、脱氨塔8、第三调节塔、二级萃取塔9以及第二脱溶剂塔10和依次连接设置的粗酚槽12、溶剂循环槽13、萃取物槽14；
一次除油池1用于对煤化工废水进行一次除油处理；第一调节塔3用于将一次除油后的废水的pH值调节至≤7；一级萃取塔4用于对一次除油后pH值≤7的废水进行一级萃取脱酚处理；脱酸塔5用于对一级萃取脱酚后的废水进行脱酸处理；第二调节塔用于将脱酸后的废水的pH值调节至≥8；脱氨塔8用于对pH值≥8的废水进行脱氨处理；第三调节塔用于将脱氨后的废水的pH值调节至≤7；二级萃取塔9用于对脱氨后pH值≤7 的废水进行二级萃取脱酚处理；第二脱溶剂塔10用于对二级萃取脱酚后的废水进行二次脱溶剂处理；脱酸塔5的出酸口与第一调节塔、第二调节塔的进酸口相连；在脱酸塔5与第二调节塔之间还设置有第一脱溶剂塔7，用于对脱酸后的废水进行一次脱溶剂处理；萃取物槽14、酚塔6以及粗酚槽12依次连接，萃取物槽14的进口与一级萃取塔4、二级萃取塔9的萃取物出口相连；酚塔6用于对一级萃取脱酚得到的第一萃取物、二级萃取脱酚得到的第二萃取物进行精制提酚；粗酚槽12用于容纳酚塔6制得的粗酚；溶剂循环槽13的进口与第一脱溶剂塔7、第二脱溶剂塔10、酚塔6的溶剂出口相连，溶剂循环槽13的出口与一级萃取塔4、二级萃取塔9的萃取剂进口相连。
生化处理单元包括依次连接的二次除油池15、降解池16、生化反应池17、一次沉淀池18、二次除油池15，用于对从第二脱溶剂塔10流出的废水进行二次除油处理；
降解池16，用于对从预处理单元流出的废水进行厌氧菌降解处理；以及，生化反应池17，用于对厌氧菌降解处理后的废水进行脱氮除碳处理；
一次沉淀池18，用于对脱氮除碳处理后的废水进行泥水分离；一次沉淀池18的出泥口与降解池16的进口相连，用于将泥水分离步骤得到的第一污泥部分回用至厌氧菌降解处理步骤中。
深度处理单元包括依次连接的混凝沉淀池19、膜过滤装置20和依次连接的污泥浓缩池23和污泥脱水装置24
混凝沉淀池19，用于对从生化处理单元流出的废水进行混凝沉淀处理；以及膜过滤装置20，用于对混凝沉淀处理后的废水进行反渗透膜处理；
污泥浓缩池23和污泥脱水装置24，混凝沉淀池19的出泥口、一次沉淀池18的出泥口与污泥浓缩池23的进口连接，污泥脱水装置24的出水口与降解池16的进水口相连。
蒸发结晶单元包括MVR蒸发结晶装置21，用于将从深度处理单元流出的废水加热，结晶分离渣盐，得到净化水；
在其他实施例中，煤化工废水处理系统还可以包括原料储罐2；
原料储罐2，原料储罐2的进口连接一次除油池1的出口，原料储罐2的出口连接第一调节塔3的进口；
在其他实施例中，煤化工废水处理系统还可以包括油池11，油池11用于回收一次除油池1一次去除的油类废物；
在其他实施例中，煤化工废水处理系统还可以包括浮渣收集池22，浮渣收集池22的进口连接二次除油池15的出渣口。
相应反应釜/塔/反应池/装置参数为：
第一调节塔3的塔釜液位为1.3～2m，塔底压力为50～200KPa，塔顶压力为 370～410KPa；
脱酸塔5的塔顶温度为35～50℃、压力为0.2～0.6MPa；塔底温度为130～145℃、压力0.22～0.62MPa；回流比为1～7，塔板数为25～45；
脱氨塔8的塔顶温度为135～150℃、压力为0.3～0.7MPa；塔底温度为148～160℃、压力为0.33～0.73MPa；回流比为2～9，塔板数为35～45；
一级萃取塔4的操作温度为25～65℃、压力为90～350KPa，溶剂比为2:1～9:1，塔板数为70～90；
二级萃取塔9的操作温度为25～65℃、压力为90～350KPa，溶剂比为2:1～9:1，塔板数为70～90；
二次脱溶剂塔10的塔顶温度为88～105℃，塔釜温度为95～110℃；
酚塔6的塔顶温度95～105℃，塔釜温度为205～215℃；
二次除油池15的温度为40～60℃，溶气压力为0.4～0.6Mpa，气水比为30～50％；
降解池16的水力停留时间为(HRT)15～20h，pH为5～7，温度保持在21～32℃，溶解氧含量为0～0.5mg/L；
生化反应池17包括依次连接的一级好氧池、厌氧池和二级好氧池，所述一级好氧池的进口与所述降解池16出口相连接，所述二级好氧池与所述一次沉淀池18的进口相连接；所述厌氧池的温度为35～38℃，溶解氧含量控制在0～0.5mg/L，pH值为6.5～7.2，水力停留时间1.5～2h；所述一级好氧池和所述二级好氧池的参数均为温度为29～37℃，溶解氧含量控制在2～8mg/L，水力停留时间7～9h，pH值为8.0～8.5；；
一次沉淀池18的pH为6～9，沉淀处理时间为3～5h，污泥回流比50％～200％；混凝沉淀池19的水温为20～30℃，沉降时间为4～6h，污泥回流比50％～100％；
膜过滤装置20的操作压力为0.05Mpa；
MVR蒸发结晶装置21的第一次蒸发浓缩的温度为50～150℃，结晶温度50～100℃；第二次蒸发结晶时，蒸发浓缩的温度为50～150℃，结晶温度为30～50℃。
组合填料具体为：其结构是将塑料圆片压扣改成双圈大塑料环，将醛化纤维或涤纶丝压在环的环圈上，使纤维束均匀分布；内圈是雪花状塑料枝条，既能挂膜，又能有效切割气泡，提高氧的转移速率和利用率，组合填料具体结构如图2～图3所示。使水气生物膜得到充分交换，使水中的有机物得到处理。组合填料在强大的曝气湍激的水气流的情况下较为理想的选用填料。
实施例2
本实施例提供的煤化工废水处理方法包括如下步骤：
(1)预处理工艺
废水进入一次除油池经脱除废水中的轻油、重油和部分油渣后，送入第一调节塔上部，轻、重油作为产品回收。第一调节塔下部通入来自脱酸塔的含硫化氢酸性气体原料污水与含硫化氢气体充分接触传质后，pH值降至7以下，从塔底经第一调节塔釜液泵输送进一级萃取塔，第一调节塔塔内含硫化氢的气体，经在塔顶来自第二脱溶剂塔的塔釜液淋洗后由塔顶采出，进硫磺装置。来自第一调节塔釜液的污水进入一级萃取塔顶部，底部进来自溶剂循环槽的萃取剂甲基叔戊基醚，在酸性条件下，废水中的酚油被萃取至萃取相中，萃取相从塔顶排出至酚回收塔，萃取剂进萃取物槽，废水从塔底排出至脱酸塔。脱酸塔用于脱除所述除酚油后废水中的酸性气体，塔顶气相经冷凝去第一调节塔，塔釜液进入第一脱溶剂塔，脱除废水中少量溶剂后，加氢氧化钾调节pH大于8后进入脱氨塔。脱氨塔内脱除废水中的氨，塔顶气相含水蒸气75％的氨气进氨精制系统，塔釜液与废水调节池内硫酸混合调节pH至7以下后进二级萃取塔。污水在二级萃取塔内与萃取剂充分接触后，剩余的油类及酚类绝大部分被萃取到溶剂中，萃取相进入萃取物槽，水相进入第二脱溶剂塔。第二脱溶剂塔釜液去尾气吸收塔顶喷淋洗涤、去第一调节塔顶洗氨、去脱酸塔顶作为回流、去第一脱溶剂塔作为回流、作为第二脱溶剂塔本身的回流、去生化处理单元，第二脱溶剂塔和第一脱溶剂塔塔顶采出萃取物全部进入萃取物槽，经分离后进入酚塔。
(2)生化处理工艺
由于预处理单元处理后污水中的石油类含量为180mg/L，因此，在工艺流程的前段设置了溶气二次除油池，以确保生化处理系统进水要求。溶气二次除油后污水进入降解池，通过厌氧生物菌使水中大分子、难降解的有机物开环断链，转变为小分子、易生物降解的有机物，降解池内安装组合填料，填料采用自由摆动支架，进水采用旋转布水器，池底设有穿孔管，实现均匀布水。采用专利技术“SH-A节能型强化生物脱氮除碳工艺”依次进行好氧-厌氧-好氧处理，脱除来自降解反应池废水中的有机物和氨氮。生化反应池出水进入一次沉淀池分离泥水混合液，分离出的污泥通过静压排泥排到污泥储池，然后送往污泥浓缩池处理，废水进入混凝沉淀池。
(3)深度处理工艺
混合反应池内投加混凝药剂聚丙烯酰胺，二沉池的出水与药剂充分混合后，出水进入混凝沉淀池，池内投加的混凝药剂能够吸附污水中未被去除的有机物和悬浮物质，结合成较大颗粒，通过重力作用沉淀下来，从而达到进一步去除有机物和悬浮物的目的。经混合沉淀池后出水进高效防堵塞的反渗透膜处理装置，得到透析水和浓缩水，透析水回用。
(4)蒸发结晶工艺
来自反渗透膜浓缩水首先送入汽水分离器。汽水分离器与蒸发器形成强制循环蒸发器，含盐废水在蒸发器中被加热，气液在汽水分离器中分离，浓缩至25％的废水送到结晶罐进一步结晶分离，母液经母液预热器预热后进入汽水分离器继续蒸发。蒸发产生的蒸汽进入压缩机被压缩后，然后进入蒸发器作为加热介质。蒸发器中冷凝下来的冷凝水进入冷凝水罐，通过冷凝水泵进入母液预热器加热母液。为防止物料在蒸发器内结垢，通过添加颗粒密度为1200～3000kg/m3，粒径为0.32～3.8mm，比热为0.5～1.5kJ/kg·K的惰性粒子三氧化二铝和聚四氟乙烯复合材料颗粒，在设备内部形成三相流，达到防垢的目的。
相应反应釜/塔/反应池/装置的操作参数为：
第一调节塔：塔釜液位1.3m，塔底压力50Kpa，塔顶压力370Kpa；
脱酸塔：塔顶温度35℃、压力0.2Mpa，塔底温度130℃、压力0.22Mpa，回流比为1，塔板数25；
脱氨塔：塔顶温度135℃、压力0.3，塔底温度148℃、压力0.33，回流比2，塔板数35；
一级萃取塔：操作温度25℃、压力90Kpa，溶剂比2:1，塔板数70；
二级萃取塔：操作温度25℃、压力90Kpa，溶剂比2:1，塔板数70；
二次脱溶剂塔的塔顶温度为88℃，塔釜温度为95℃；
酚塔：塔顶温度95℃，塔釜温度为205℃；
二次除油池：温度40℃，溶气压力0.4Mpa，气水比30％；
降解池：水力停留时间为(HRT)15h，pH为5，温度保持在21℃，溶解氧含量为0mg/L；
生化反应池：厌氧池：温度为35℃，溶解氧含量控制在0mg/L，pH值为6.5，水力停留时间1.5；一级好氧池：温度为29℃；溶解氧含量控制在2mg/L，水力停留时间7h，pH值为8.0；二级好氧池：温度为29℃；溶解氧含量控制在2mg/L，水力停留时间7h，pH值为8.0；
一次沉淀池：pH6，沉淀处理时间3h，污泥回流比50％；
混凝沉淀池：水温20℃，沉降时间4h，污泥回流比50％；
膜过滤装置：操作压力0.05Mpa；
MVR蒸发结晶装置：蒸发浓缩的温度为50℃，结晶温度50℃，得到硫酸钠结晶；二次蒸发结晶时，蒸发浓缩的温度为50℃，结晶温度为30℃，得到氯化钠结晶。
实施例3
除以下内容外，其余与实施例2相同。
萃取剂为甲基异丁基酮、混凝药剂为聚合氯化铝。
相应反应釜/塔/反应池/装置参数为：
第一调节塔：塔釜液位1.7m，塔底压力130Kpa，塔顶压力400Kpa；
脱酸塔：塔顶温度40℃、压力0.4Mpa，塔底温度138℃、压力0.42Mpa，回流比5，塔板数30；
脱氨塔：塔顶温度140℃、压力0.4Mpa，塔底温度155℃、压力0.53Mpa，回流比5，塔板数41；
一级萃取塔：操作温度65℃、压力350Kpa，溶剂比9:1，塔板数90；
二级萃取塔：操作温度65℃、压力350Kpa，溶剂比9:1，塔板数90；
二次脱溶剂塔的塔顶温度为105℃，塔釜温度为110℃；
酚塔的塔顶温度105℃，塔釜温度为215℃；
二次除油池的温度为60℃，溶气压力为0.6Mpa，气水比为50％；
降解池的水力停留时间为(HRT)20h，pH为7，温度保持在32℃，溶解氧含量为0.5mg/L；
生化反应池：厌氧池：温度为38℃，溶解氧含量控制在0.5mg/L，pH值为7.2，水力停留时间2h；一级好氧池：温度为37℃；溶解氧含量控制在8mg/L，水力停留时间9h，pH值为8.5；二级级好氧池：温度为37℃；溶解氧含量控制在8mg/L，水力停留时间9h，pH值为8.5；
一次沉淀池：pH为9，沉淀处理时间为5h，污泥回流比200％；
混凝沉淀池：水温为30℃，沉降时间为6h，污泥回流比100％；
膜过滤装置：操作压力为0.05Mpa；
MVR蒸发结晶装置：第一次蒸发浓缩的温度为150℃，结晶温度100℃，得到硫酸钠结晶；第二次蒸发结晶时，蒸发浓缩的温度为150℃，结晶温度为50℃，得到氯化钠结晶。
实施例4
除以下内容外，其余与实施例2相同。
萃取剂为碳酸二甲酯、混凝药剂为聚合硫酸铁。
相应反应釜/塔/反应池/装置参数为：
第一调节塔：塔釜液位2m，塔底压力200Kpa，塔顶压力410Kpa；
脱酸塔：塔顶温度50℃、压力0.6Mpa，塔底温度145℃、压力00.62Mpa，回流比7，塔板数45；
脱氨塔：塔顶温度150℃、压力0.7Mpa，塔底温度160℃、压力0.73Mpa，回流比9， 塔板数45；
一级萃取塔：操作温度25℃、压力90Kpa，溶剂比2:1，塔板数70；
二级萃取塔：操作温度35℃、压力200Kpa，溶剂比5:1，塔板数80；
二次脱溶剂塔：塔顶温度为99℃，塔釜温度为100℃；
酚塔：塔顶温度96℃，塔釜温度为210℃；
二次除油池：温度为45℃，溶气压力为0.5Mpa，气水比为40％；
降解池：水力停留时间为(HRT)18h，pH为6，温度保持在27℃，溶解氧含量为0.3mg/L；
生化反应池：厌氧池：温度为37℃，溶解氧含量控制在0.4mg/L，pH值为6.8，水力停留时间2h；一级好氧池：温度为35℃；溶解氧含量控制在4mg/L，水力停留时间8h，pH值为8.3；二级级好氧池：温度为37℃；溶解氧含量控制在8mg/L，水力停留时间9h，pH值为8.5；
一次沉淀池：pH为7，沉淀处理时间4h，污泥回流比160％；
混凝沉淀池：水温15℃，沉降时间5h，污泥回流比80％。
膜过滤装置：操作压力为0.05Mpa；
MVR蒸发结晶装置：第一次蒸发浓缩的温度为130℃，结晶温度80℃，得到硫酸钠结晶；第二次蒸发结晶时，蒸发浓缩的温度为120℃，结晶温度为45℃，得到氯化钠结晶。
对比例1
除以下内容外，其余内容与实施例2相同。
预处理工艺包括以下步骤：
对煤化工废水依次进行一次除油处理、一级萃取脱酚处理、脱酸处理；
将脱酸后的废水的pH值调节至≥8，之后进行脱氨处理；
对脱氨后的废水依次进行二级萃取脱酚处理和二次脱溶剂处理。
对比例2
除以下内容外，其余内容与实施例2相同。
预处理工艺包括以下步骤：对煤化工废水依次进行一次除油处理、脱酸处理、脱氨处理、萃取脱酚处理和二次脱溶剂处理。
实验例
对本申请的实施例及对比例进水及处理后指标进行检测，结果如下：
表1：废水进水规格表
表2：预处理出水指标
表3：生化处理、深度处理出水指标

表4：蒸发结晶处理产水指标
显然，上述实施例仅仅是为清楚地说明所作的举例，而并非对实施方式的限定。对于所属领域的普通技术人员来说，在上述说明的基础上还可以做出其它不同形式的变化或变动。这里无需也无法对所有的实施方式予以穷举。而由此所引伸出的显而易见的变化或变动仍处于本发明创造的保护范围之中。

Claims (10)

  1. 一种煤化工废水处理方法，包括依次对煤化工废水进行预处理、生化处理、深度处理以及蒸发结晶的工艺；其特征在于，所述预处理工艺包括以下步骤：
    S11、对所述煤化工废水进行一次除油处理；
    S12、将一次除油后的废水的pH值调节至≤7，之后进行一级萃取脱酚处理；
    S13、对一级萃取脱酚后的废水进行脱酸处理；
    S14、将脱酸后的废水的pH值调节至≥8，之后进行脱氨处理；
    S15、将脱氨后的废水的pH值调节至≤7，之后进行二级萃取脱酚处理；
    S16、对二级萃取脱酚后的废水进行二次脱溶剂处理。
  2. 根据权利要求1所述的煤化工废水处理方法，其特征在于，选自如下特征中的任意一个：
    A.将步骤S13脱酸得到的酸液作为pH调节剂，用于步骤S12和/或步骤S15；
    B.在步骤S14中还包括一次脱溶剂步骤：先对所述脱酸后的废水进行一次脱溶剂处理，再对一次脱溶剂后的废水进行脱氨处理；
    C.将步骤S12一级萃取脱酚得到的第一萃取物和/或步骤S15二级萃取脱酚得到的第二萃取物精制提酚，得到粗酚；
    D.将步骤S14一次脱溶剂得到的第一溶剂、步骤S16二次脱溶剂得到的第二溶剂、所述精制提酚步骤得到的第三溶剂中的至少一种，作为萃取剂回用至步骤S12和/或步骤S15中。
  3. 根据权利要求1或2所述的煤化工废水处理方法，其特征在于，所述生化处理工艺包括如下步骤：
    对完成所述预处理工艺后的废水依次进行厌氧菌降解处理和脱氮除碳处理；
    可选地，在进行所述厌氧菌降解处理之前还包括二次除油处理；
    可选地，在进行所述脱氮除碳处理之后还包括泥水分离步骤；
    可选地，将所述泥水分离步骤得到的第一污泥部分回用至所述厌氧菌降解处理步骤中。
  4. 根据权利要求3所述的煤化工废水处理方法，其特征在于，所述深度处理工艺包括如下步骤：对完成所述生化处理工艺后的废水依次进行混凝沉淀处理和反渗透膜处理；和/或，
    所述蒸发结晶工艺包括如下步骤：将完成所述深度处理工艺后的废水加热，结晶分离渣盐，即得净化水；
    可选地，将所述混凝沉淀处理得到的第二污泥和/或所述泥水分离步骤得到的第一污泥脱水，所得水相与所述二次除油处理后的废水混合。
  5. 一种煤化工废水处理系统，包括依次连接设置的预处理单元、生化处理单元、深度处理单元以及蒸发结晶单元；其特征在于，所述预处理单元包括依次连接设置的一次除油池(1)、第一调节塔(3)、一级萃取塔(4)、脱酸塔(5)、第二调节塔、脱氨塔(8)、第三调节塔、二级萃取塔(9)以及第二脱溶剂塔(10)；其中，
    所述一次除油池(1)用于对煤化工废水进行一次除油处理；
    所述第一调节塔(3)用于将一次除油后的废水的pH值调节至≤7；
    所述一级萃取塔(4)用于对一次除油后pH值≤7的废水进行一级萃取脱酚处理；
    所述脱酸塔(5)用于对一级萃取脱酚后的废水进行脱酸处理；
    所述第二调节塔用于将脱酸后的废水的pH值调节至≥8；
    所述脱氨塔(8)用于对pH值≥8的废水进行脱氨处理；
    所述第三调节塔用于将脱氨后的废水的pH值调节至≤7；
    所述二级萃取塔(9)用于对脱氨后pH值≤7的废水进行二级萃取脱酚处理；
    所述第二脱溶剂塔(10)用于对二级萃取脱酚后的废水进行二次脱溶剂处理。
  6. 根据权利要求5所述的煤化工废水处理系统，其特征在于，选自如下特征中的任意一个：
    A.所述脱酸塔(5)的出酸口与所述第一调节塔和/或所述第二调节塔的进酸口相连；
    B.在所述脱酸塔(5)与所述第二调节塔之间还设置有第一脱溶剂塔(7)，用于对所述脱酸后的废水进行一次脱溶剂处理；
    C.所述预处理单元还包括依次连接设置的萃取物槽(14)、酚塔(6)以及粗酚槽(12)，所述萃取物槽(14)的进口与所述一级萃取塔(4)和/或所述二级萃取塔(9)的萃取物出口相连；所述酚塔(6)用于对所述一级萃取脱酚得到的第一萃取物和/或所述二级萃 取脱酚得到的第二萃取物进行精制提酚；所述粗酚槽(12)用于容纳所述酚塔(6)制得的粗酚；
    D.所述预处理单元还包括溶剂循环槽(13)，所述溶剂循环槽(13)的进口与所述第一脱溶剂塔(7)、所述第二脱溶剂塔(10)、所述所述酚塔(6)中的至少一个的溶剂出口相连，所述溶剂循环槽(13)的出口与所述一级萃取塔(4)和/或所述二级萃取塔(9)的萃取剂进口相连。
  7. 根据权利要求5或6所述的煤化工废水处理系统，其特征在于，所述生化处理单元包括：
    降解池(16)，用于对从所述预处理单元流出的废水进行厌氧菌降解处理；以及，生化反应池(17)，用于对所述厌氧菌降解处理后的废水进行脱氮除碳处理；
    可选地，所述生化处理单元还包括二次除油池(15)，用于对从所述第二脱溶剂塔(10)流出的废水进行二次除油处理；
    可选地，所述生化处理单元还包括一次沉淀池(18)，用于对所述脱氮除碳处理后的废水进行泥水分离；
    可选地，所述一次沉淀池(18)的出泥口与所述降解池(16)的进口相连，用于将所述泥水分离步骤得到的第一污泥部分回用至所述厌氧菌降解处理步骤中。
  8. 根据权利要求7所述的煤化工废水处理系统，其特征在于，所述深度处理单元包括：混凝沉淀池(19)，用于对从所述生化处理单元流出的废水进行混凝沉淀处理；以及膜过滤装置(20)，用于对所述混凝沉淀处理后的废水进行反渗透膜处理；
    可选地，所述深度处理单元还包括依次连接的污泥浓缩池(23)和污泥脱水装置(24)，所述混凝沉淀池(19)的出泥口和/或所述一次沉淀池(18)的出泥口与所述污泥浓缩池(23)的进口连接，所述污泥脱水装置(24)的出水口与所述降解池(16)的进水口相连。
  9. 根据权利要求5所述的煤化工废水处理系统，其特征在于，所述蒸发结晶单元包括MVR蒸发结晶装置(21)，用于将从所述深度处理单元流出的废水加热，结晶分离渣盐，得到净化水；
    可选地，所述煤化工废水处理系统还包括：
    原料储罐(2)，所述原料储罐(2)的进口连接所述一次除油池(1)的出口，所述原料储罐(2)的出口连接所述第一调节塔(3)的进口；
    浮渣收集池(22)，所述浮渣收集池(22)的进口连接所述二次除油池(15)的出渣口。
  10. 根据权利要求5或6所述的煤化工废水处理系统，其特征在于，选自如下特征中的任意一种：
    I.所述第一调节塔(3)的塔釜液位为1.3～2m，塔底压力为50～200KPa，塔顶压力为370～410KPa；
    II.所述脱酸塔(5)的塔顶温度为35～50℃、压力为0.2～0.6MPa；塔底温度为130～145℃、压力0.22～0.62MPa；回流比为1～7，塔板数为25～45；
    III.所述脱氨塔(8)的塔顶温度为135～150℃、压力为0.3～0.7MPa；塔底温度为148～160℃、压力为0.33～0.73MPa；回流比为2～9，塔板数为35～45；
    IV.所述一级萃取塔(4)的操作温度为25～65℃、压力为90～350KPa，溶剂比为2:1～9:1，塔板数为70～90；
    V.所述二级萃取塔(9)的操作温度为25～65℃、压力为90～350KPa，溶剂比为2:1～9:1，塔板数为70～90；
    VI.所述二次脱溶剂塔(10)的塔顶温度为88～105℃，塔釜温度为95～110℃；
    VII.所述酚塔(6)的塔顶温度95～105℃，塔釜温度为205～215℃；
    Ⅷ.所述二次除油池(15)的温度为40～60℃，溶气压力为0.4～0.6Mpa，气水比为30～50％；
    Ⅸ.所述降解池(16)的水力停留时间为15～20h，pH为5～7，温度保持在21～32℃，溶解氧含量为0～0.5mg/L；
    Ⅹ.所述生化反应池(17)包括依次连接的一级好氧池、厌氧池和二级好氧池，所述一级好氧池的进口与所述降解池(16)出口相连接，所述二级好氧池与所述一次沉淀池(18)的进口相连接；所述厌氧池的温度为35～38℃，溶解氧含量控制在0～0.5mg/L，pH值为6.5～7.2，水力停留时间1.5～2h；所述一级好氧池和所述二级好氧池的参数均为温度为29～37℃，溶解氧含量控制在2～8mg/L，水力停留时间7～9h，pH值为8.0～8.5；
    Ⅺ.所述一次沉淀池(18)的pH为6～9，沉淀处理时间3～5h，污泥回流比50％～200％；
    Ⅻ.所述混凝沉淀池(19)的水温为20～30℃，沉降时间4～6h，污泥回流比50％～100％；
    XIII.所述膜过滤装置(20)的操作压力为0.05Mpa；
    XIV.所述MVR蒸发结晶装置(21)第一次蒸发浓缩的温度为50～150℃，结晶温度50～100℃；第二次蒸发结晶时，蒸发浓缩的温度为50～150℃，结晶温度为30～50℃。
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