WO2023173927A1 - 一种循环冷却水零排污处理系统及方法 - Google Patents

一种循环冷却水零排污处理系统及方法 Download PDF

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WO2023173927A1
WO2023173927A1 PCT/CN2023/072494 CN2023072494W WO2023173927A1 WO 2023173927 A1 WO2023173927 A1 WO 2023173927A1 CN 2023072494 W CN2023072494 W CN 2023072494W WO 2023173927 A1 WO2023173927 A1 WO 2023173927A1
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Prior art keywords
water
unit
outlet
salt
storage tank
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PCT/CN2023/072494
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English (en)
French (fr)
Inventor
陈爱民
聂明
曹宏伟
闫红梅
刘宝山
Original Assignee
天津正达科技有限责任公司
中海油天津化工研究设计院有限公司
中海油能源发展股份有限公司
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Publication of WO2023173927A1 publication Critical patent/WO2023173927A1/zh

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    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D1/00—Evaporating
    • B01D1/26—Multiple-effect evaporating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D9/00—Crystallisation
    • B01D9/0018—Evaporation of components of the mixture to be separated
    • 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
    • C01D3/06—Preparation by working up brines; seawater or spent lyes
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D9/00—Crystallisation
    • B01D2009/0086—Processes or apparatus therefor
    • 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
    • C02F1/22—Treatment of water, waste water, or sewage by freezing
    • 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
    • C02F1/24—Treatment of water, waste water, or sewage by flotation
    • 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
    • C02F1/444—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by ultrafiltration or microfiltration
    • 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
    • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/4602—Treatment of water, waste water, or sewage by electrochemical methods for prevention or elimination of deposits
    • 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
    • C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/461—Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
    • C02F1/46104—Devices therefor; Their operating or servicing
    • 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
    • C02F1/50—Treatment of water, waste water, or sewage by addition or application of a germicide or by oligodynamic treatment
    • 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
    • C02F1/5209—Regulation methods for flocculation or precipitation
    • 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
    • C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
    • 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
    • C02F1/5281—Installations for water purification using chemical agents
    • 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
    • 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
    • C02F2001/5218—Crystallization
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/02—Non-contaminated water, e.g. for industrial water supply
    • C02F2103/023—Water in cooling circuits
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2209/00—Controlling or monitoring parameters in water treatment
    • C02F2209/11—Turbidity
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2303/00—Specific treatment goals
    • C02F2303/08—Corrosion inhibition
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents

Definitions

  • the invention belongs to the technical field of circulating cooling water treatment, and relates to a circulating cooling water zero-discharge treatment system and method.
  • Circulating cooling water treatment technology is now widely used in various fields such as petroleum and chemical industry, and its sewage discharge accounts for about 40 to 50% of the total discharge of enterprises.
  • the restrictions on the amount of sewage discharged by enterprises are becoming more and more obvious, and the standards for sewage discharge are also becoming increasingly strict, which directly affects the development of enterprises. Therefore, effectively reducing the discharge volume of circulating cooling water can significantly reduce the drainage pressure of enterprises.
  • high concentration rate technology for circulating water systems has been widely used and is helpful in reducing system drainage, it has high requirements on water quality and system selection, and has great application limitations.
  • the existing zero-discharge technology mostly uses the reverse osmosis process to concentrate the circulating water, and then uses the evaporation and crystallization process to crystallize and evaporate the circulating water to form miscellaneous salts and then perform subsequent treatment.
  • the lack of relevant standards limits the secondary use of miscellaneous salt, which is often treated as hazardous waste and the treatment cost is relatively high.
  • the existing technology adds more chemicals to the circulating water system, resulting in higher treatment costs.
  • the present invention provides a circulating cooling water zero-discharge treatment system and method.
  • the circulating cooling water zero-discharge treatment system and method of the present invention can realize zero-discharge of circulating cooling water, can realize the reuse of resources in the system, reduce the dosage of external chemicals, and have low operating costs.
  • the final crystallized products are sodium chloride and hydrated sodium sulfate, realizing the secondary resource utilization of salt.
  • the present invention specifically achieves the above object through the following technical solutions.
  • the invention provides a circulating cooling water zero-discharge treatment system, which system includes circulating water and A filtration unit connected to the water supply port of the system, and a side filter backwash water turbidity reduction unit connected to the sewage outlet of the circulating water system.
  • the side filter backwash water turbidity reduction unit is connected to a high-efficiency turbidity reduction unit and a salt separation unit in turn, wherein
  • the salt separation unit is provided with a produced water outlet and a concentrated water outlet, which are respectively connected to the produced water storage tank and the concentrated water storage tank.
  • the concentrated water storage tank is connected to the hardness removal unit.
  • the hardness removal unit is provided with a salt scale discharge outlet.
  • the three outlets of the water production storage tank are respectively connected to the electrolysis unit, evaporation crystallization unit, and bipolar membrane unit; wherein the filtration unit is a microfiltration or ultrafiltration device , the sodium hypochlorite outlet of the electrolysis unit is connected to the dosing port of the circulating water system; the acid liquid and alkali liquid produced by the bipolar membrane unit are stored in the acid liquid storage tank and the alkali liquid storage tank respectively.
  • the high-efficiency turbidity reduction unit is also provided with a water outlet of the high-efficiency turbidity reduction unit connected to the water supply port of the circulating water system.
  • the side filter backwash water turbidity reduction unit is microfiltration or ultrafiltration;
  • the high-efficiency turbidity reduction unit is a flocculation sedimentation tank, a high-efficiency sedimentation tank or a gas Floating sedimentation tank.
  • the hardness removal unit is an electrochemical hardness removal unit or a chemical hardness removal unit.
  • each treatment unit is a skid design.
  • the present invention also provides a method for the above-mentioned treatment system to be used for zero-discharge treatment of circulating cooling water.
  • the method includes the following steps:
  • the sewage treatment external drainage is treated by microfiltration or ultrafiltration devices and enters the circulating water system as supplementary water.
  • the sewage generated by the circulating water system is discharged from the sewage outlet and enters the side filter backwash water turbidity reduction unit for turbidity reduction treatment until the effluent is discharged.
  • Turbidity is 50NTU;
  • the produced water in the produced water storage tank is divided into three parts. Most of the produced water enters the evaporation and crystallization unit for evaporation and crystallization to obtain sodium chloride, which is discharged or utilized as a resource. A part of the produced water enters the electrolysis unit and undergoes electrolysis to obtain sodium hypochlorite solution for circulation. Dosing port of the circulating water system; part of the produced water enters the bipolar membrane unit for electrolysis to obtain acid liquid and alkali liquid, which are stored in the acid liquid storage tank and alkali liquid storage tank respectively as a pH regulator for the circulating water system;
  • the concentrated water in the concentrated water storage tank enters the hardness removal unit for hardness removal treatment to obtain salt scale and concentrated water after the hardness removal, and the salt scale is discharged; the concentrated water after the hardness removal is then subjected to freezing crystallization treatment to obtain hydrated sodium sulfate, Disposal or utilization of resources.
  • the effluent turbidity after treatment by the ultrafiltration device used as water replenishment in step 1) is less than 0.5 NTU.
  • the high-efficiency turbidity reduction unit in step 2) is a flocculation sedimentation tank, and the added flocculant or coagulant aid is polymeric ferric sulfate, polyaluminum chloride and/or polyethylene chloride. Acrylamide.
  • the zero-discharge treatment method for circulating cooling water of the present invention it is preferable that all the effluent from the high-efficiency turbidity reduction unit enters the salt separation unit, or a part of the effluent is returned to the circulating cooling water system as supplementary water, and the remaining part of the effluent enters the salt separation unit.
  • the zero-discharge treatment method for circulating cooling water of the present invention it is preferred to add 50 to 200 ppm of bactericide to the circulating water system regularly or continuously to keep the residual chlorine concentration in the water at 0.5 to 1.0 ppm; add it to the system regularly or continuously as needed. Add 5 to 100 ppm highly effective corrosion and scale inhibitors to control the adhesion rate and corrosion rate indicators of the system.
  • the present invention has the following technical features:
  • the treatment system of the present invention gives full play to the concentration characteristics of the circulating cooling water system and replaces the reverse osmosis concentration technology used in the existing zero-discharge technology.
  • the method of the present invention relaxes the restrictions on the quality of replenishing water and lowers the conductivity index of replenishing circulating cooling water. As high as 50,000 ⁇ 100,000us/cm, it greatly reduces the water quality requirements and broadens the sources of water. It can replenish the sewage originally discharged by the enterprise to the circulating cooling water system, saving the corresponding fresh water and sewage discharge costs.
  • part of the sodium chloride solution is processed by a bipolar membrane process to produce a certain concentration of acid and alkali liquid, which is used for pH adjustment of the circulating water system and turbidity reduction unit; part of The sodium chloride solution is treated by an electrolysis process to produce a certain concentration of sodium hypochlorite solution that is returned to the system to control the growth of fungi and promote COD degradation.
  • the invention is equipped with a salt separation unit to separate and concentrate the incoming water to achieve the purpose of salt separation, improve the purity of sodium chloride and hydrated sodium sulfate, thereby realizing the secondary utilization of salt resources and avoiding the production of miscellaneous salts that increase the Enterprise processing burden.
  • the present invention can concentrate the salt content of circulating water to about 10% while the circulating cooling water system operates stably.
  • the treatment method of the present invention only treats the side filter backwash water, and uses processes such as turbidity reduction, hardness removal, mass separation and concentration, evaporation and crystallization to gradually reduce the amount of water, and finally discharge the salt from the system.
  • the waste liquid generated by each process is returned to the system, achieving zero discharge of circulating cooling water, and the investment and operating costs are also significantly reduced compared with the traditional zero discharge process; at the same time, supplemented by bipolar membrane and electrolysis technology, resources within the system can be reused. , reduce the dosage of external medicine and reduce operating costs.
  • Figure 1 is a schematic structural diagram of a circulating cooling water zero-discharge treatment system of the present invention.
  • Figure 2 is a process flow diagram of a zero-discharge treatment method for circulating cooling water according to the present invention.
  • a circulating cooling water zero-discharge treatment system includes a filter unit 1 connected to the water supply port of the circulating water system, and a side-filter backwash water turbidity reduction unit 2 connected to the sewage outlet of the circulating water system.
  • the side filter backwash water turbidity reduction unit 2 is connected to the high-efficiency turbidity reduction unit 3 and the salt separation unit 4 in turn.
  • the salt separation unit 4 is provided with a produced water outlet and a concentrated water outlet, which are respectively connected to the produced water storage tank 10 and the concentrated water outlet.
  • the water storage tank 11 is connected, and the concentrated water storage tank 11 is connected to the hardness removal unit 5.
  • the hardness removal unit 5 is provided with a liquid outlet and a salt scale discharge outlet connected to the freezing crystallization unit 8; the produced water
  • the three outlets of the storage tank 10 are respectively connected to the electrolysis unit 6, the evaporation and crystallization unit 7, and the bipolar membrane unit 9; the acid liquid outlet and the alkali liquid outlet of the bipolar membrane unit 9 are respectively connected to the acid liquid storage tank 13 and
  • the alkali storage tank 12 is connected;
  • the filtration unit 1 is a microfiltration or ultrafiltration device, and the sodium hypochlorite outlet of the electrolysis unit 6 is connected to the dosing port of the circulating water system.
  • the present invention also provides a method for the above-mentioned treatment system to be used for zero-discharge treatment of circulating cooling water.
  • the method includes the following steps:
  • the sewage treatment external drainage is treated by the microfiltration or ultrafiltration device 1 and then enters the circulating water system as supplementary water.
  • the sewage generated by the circulating water system enters the side filter backwash water turbidity reduction unit 2 from the sewage outlet outlet for turbidity reduction treatment.
  • the product water turbidity is 50NTU;
  • the produced water in the produced water storage tank 10 is divided into three parts. Most of the produced water enters the evaporation and crystallization unit 7 for evaporation and crystallization to obtain sodium chloride, which is discharged or utilized as a resource; a part of the produced water enters the electrolysis unit 6 and is electrolyzed to obtain sodium chloride. The sodium hypochlorite solution is circulated back to the dosing port of the circulating water system; part of the produced water enters the bipolar membrane unit 9 for electrolysis to obtain acid and alkali solutions, which are used as pH regulators in the circulating water system;
  • the concentrated water in the concentrated water storage tank 11 enters the hardness removal unit 5 for hardness removal treatment to obtain salt scale and hardness removal.
  • the concentrated water after dehydration then enters the freezing crystallization unit 8 to undergo freezing crystallization treatment to obtain hydrated sodium sulfate, which can be discharged or utilized as resources.
  • the salt in the circulating water system is entrained by the wind of the circulating cooling water tower, the sludge produced by the high-efficiency turbidity reduction unit, the salt scale produced by the hardness removal unit, the sodium chloride solid produced by the evaporation crystallization unit and the frozen
  • the hydrated sodium sulfate produced by the crystallization unit is discharged from the system through other channels to achieve the overall balance of salt in the system and maintain the stable fluctuation of the salt content of the circulating water within a certain range.
  • a coal chemical enterprise in Shanxi currently has one circulating cooling tower with a circulation capacity of 200m3/h.
  • the system water supply is the sewage discharged from the factory area. After being filtered by the ultrafiltration system, it is replenished into the circulating water system.
  • the conductivity of the water supply is 40000 ⁇ 50000us/cm.
  • the system performs water quality concentration, and the circulating water conductivity is 160000 ⁇ 180000us/cm; the circulating water system is equipped with a set of side filters, with a processing capacity of 40m3/h, and the side filter backwash water is about 5m3/h. The backwash water is reduced in turbidity through the side filter and backwash water.
  • the turbidity is reduced to 40-50 NTU, and then enters the high-efficiency turbidity reduction unit.
  • the turbidity reduction unit By adding flocculants and coagulants in the high-efficiency turbidity reduction unit, the suspended solids in the water are precipitated and filtered through the sludge press.
  • Equipment discharge system the effluent turbidity of the high-efficiency turbidity reduction unit is about 10 NTU, and then enters the salt separation unit for treatment; the salt separation unit produces two streams of produced water and concentrated water, which enter the produced water storage tank and concentrated water storage tank respectively.
  • the electrolysis unit can produce 3-10g/L sodium hypochlorite solution for return to the circulating water.
  • the system sterilizes and promotes COD degradation; the bipolar membrane unit can produce dilute acid and dilute alkali with a concentration of 3 to 5%, which are stored in dilute acid storage tanks and dilute alkali storage tanks respectively, and are added to the circulating water system as needed. Adjust system pH.
  • the concentrated water storage tank contains sodium sulfate solution with a higher concentration. It first enters the hardness removal unit to remove calcium ions.
  • the calcium ion removal rate is 80-90%, forming calcium carbonate scale and being discharged from the system in solid form; the water is discharged from the hardness removal unit.
  • hydrated sodium sulfate is formed, which is discharged from the system in solid form, forming a secondary utilization of sodium sulfate resources.
  • the daily output of sodium chloride and hydrated sodium sulfate of the system is about 600-900kg.
  • the corrosion rate of the hanging pieces in the circulating pool is: 0.0246mm/a for carbon steel pieces and 0mm/a for stainless steel pieces, which meet the relevant requirements of national standards.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Hydrology & Water Resources (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)
  • Water Treatment By Electricity Or Magnetism (AREA)

Abstract

一种循环冷却水零排污处理系统及方法，该系统包括与循环水系统相连的过滤单元（1）和旁滤反洗水降浊单元（2），旁滤反洗水降浊单元（2）依次与高效降浊单元（3）、分盐单元（4）相连，其中分盐单元（4）设有产水出口和浓水出口，分别与产水储罐（10）和浓水储罐（11）连接，浓水储罐（11）与除硬单元（5）相连，除硬单元（5）设置有与冷冻结晶单元（8）相连的出液口和盐垢排放出口；产水储罐（10）的三个出口分别与电解单元（6）、蒸发结晶单元（7）、双极膜单元（9）相连。

Description

一种循环冷却水零排污处理系统及方法 技术领域
本发明属于循环冷却水处理技术领域，涉及一种循环冷却水零排污处理系统及方法。
背景技术
循环冷却水处理技术现已广泛应用于石油、化工等各个领域，其污水外排量约占企业排水总量的40～50％左右。随着国家环保政策的日益严格，企业的污水外排量受限越来越明显，外排水标准也日趋严格，直接影响企业发展。所以，有效减少循环冷却水的排污量，能够明显减轻企业排水压力。虽然目前针对循环水系统的高浓缩倍率技术已广泛应用，对减少系统排水量有一定帮助，但其对补水水质及系统的选择要求较高，应用局限性大。现有的零排技术多使用反渗透工艺对循环水进行浓缩，再使用蒸发结晶工艺对循环水进行结晶蒸发，形成杂盐后再进行后续处理，但由于目前国家对杂盐的二次利用并未出台相关标准，使得杂盐的二次利用受限，常按照危废进行处理，处理成本相对较高。同时，现有技术向循环水系统中投加的药剂较多，处理成本较高。
发明内容
本发明针对现有技术存在的上述不足，提供了一种循环冷却水零排污处理系统及方法。本发明循环冷却水零排污处理系统及方法能够实现循环冷却水零排污水，且能实现系统内资源再利用，减少外加药剂量，运行成本低。同时，通过分盐单元的处理，使最终结晶产物为氯化钠和水合硫酸钠，实现盐份的二次资源化利用。
本发明具体通过如下技术方案实现上述目的。
本发明提供了一种循环冷却水零排污处理系统，该系统包括与循环水 系统补水口相连的过滤单元，和与循环水系统排污口连接的旁滤反洗水降浊单元，所述的旁滤反洗水降浊单元依次与高效降浊单元、分盐单元相连，其中分盐单元设有产水出口和浓水出口，分别与产水储罐和浓水储罐连接，所述的浓水储罐与除硬单元相连，所述除硬单元设置有盐垢排放出口和与冷冻结晶单元相连的出液口；所述的产水储罐的三个出口分别与电解单元、蒸发结晶单元、双极膜单元相连；其中所述的过滤单元为微滤或超滤装置，所述的电解单元的次氯酸钠出液口与循环水系统的加药口相连；所述双极膜单元产生的酸液和碱液分别储存于酸液储罐和碱液储罐。
本发明所述的循环冷却水零排污处理系统中，优选所述的高效降浊单元还设有与循环水系统补水口相连的高效降浊单元出水口。
本发明所述的循环冷却水零排污处理系统中，优选所述的旁滤反洗水降浊单元为微滤或超滤；所述的高效降浊单元为絮凝沉淀池、高效沉淀池或气浮沉淀池。
本发明所述的循环冷却水零排污处理系统中，优选所述的除硬单元为电化学除硬单元或化学除硬单元。
本发明所述的循环冷却水零排污处理系统中，优选所述的各处理单元均为撬块化设计。
本发明还提供了一种上述处理系统用于循环冷却水零排污处理的方法，该方法包括如下步骤：
1)将污水处理外排水经微滤或超滤装置处理后作为补水进入循环水系统，循环水系统产生的排污水从排污口排出，进入旁滤反洗水降浊单元进行降浊处理至出水浊度为50NTU；
2)旁滤反洗水降浊单元出水进入高效降浊单元进一步降浊，使出水浊度小于10NTU；
3)高效降浊单元出水进入分盐单元经分盐处理得到分盐产水和分盐 浓水，分别进入产水储罐和浓水储罐；
4)产水储罐中的产水分为三部分，其中大部分产水进入蒸发结晶单元进行蒸发结晶得到氯化钠，外排或资源化利用；一部分产水进入电解单元经电解得到次氯酸钠溶液循环回循环水系统加药口；一部分产水进入双极膜单元电解得到酸液、碱液，分别存储于酸液储罐和碱液储罐，作为循环水系统pH调节剂；
5)浓水储罐中的浓水进入除硬单元进行除硬处理得到盐垢和除硬后的浓水，盐垢外排；除硬后的浓水再经冷冻结晶处理得到水合硫酸钠，外排或资源化利用。
本发明循环冷却水零排污处理方法中，优选所述步骤1)中作为补水的超滤装置处理后的出水浊度小于0.5NTU。
本发明循环冷却水零排污处理方法中，优选所述的步骤2)中高效降浊单元为絮凝沉淀池，投加的絮凝剂或助凝剂为聚合硫酸铁、聚合氯化铝和/或聚丙烯酰胺。
本发明循环冷却水零排污处理方法中，优选高效降浊单元的出水全部进入分盐单元，或者一部分出水作为补水返回循环冷却水系统，剩余部分出水进入分盐单元。
本发明循环冷却水零排污处理方法中，优选定期或连续向循环水系统中投加50～200ppm的杀菌剂，保持水中余氯浓度维持在0.5～1.0ppm；根据需要定期或连续向系统中投加5～100ppm高的效缓蚀阻垢剂，以控制系统的粘附速率和腐蚀速率指标。
与现有技术相比，本发明有如下技术特点：
本发明处理系统充分发挥了循环冷却水系统能够浓缩的特性，替代了现有零排技术中使用的反渗透浓缩技术。
本发明方法放宽了补水水质的限制，将循环冷却水补水的电导指标放 大到50000～100000us/cm，大大降低了补水水质要求，拓宽了补水的来源，可将企业原本要排放的污水回补至循环冷却水系统，节省了相应的新鲜水费用和污水排放费用。
实现系统内资源再利用，减少外购药剂成本，如部分氯化钠溶液采用双极膜工艺处理，产生一定浓度的酸液和碱液，用于循环水系统和降浊单元的pH调节；部分氯化钠溶液采用电解工艺处理，产生一定浓度的次氯酸钠溶液返回系统，用于控制菌类滋生和促进COD降解。
本发明设有分盐单元进行来水的分质浓缩，达到分盐的目的，提高了氯化钠和水合硫酸钠的纯度，进而实现盐份的资源化二次利用，避免产生杂盐而增加企业处理负担。
本发明通过多种处理单元的高效耦合，辅之高效缓蚀阻垢剂的应用，在循环冷却水系统稳定运行的同时将循环水含盐量浓缩到10％左右。本发明处理方法仅对旁滤反洗水进行处理，利用降浊、除硬、分质浓缩、蒸发结晶等工艺逐步减量化处理，最终将盐份排出系统。同时，各工艺产生的废液均返回系统，实现循环冷却水零排污，投资及运行成本也较传统零排工艺大幅度降低；同时，辅之双极膜、电解技术，实现系统内资源再利用，减少外加药剂量，降低运行成本。
附图说明
图1为本发明一种循环冷却水零排污处理系统结构示意图。
图2为本发明一种循环冷却水零排污处理方法的工艺流程图。
其中，1、过滤单元；2、旁滤反洗水降浊单元；3、高效降浊单元；4、分盐单元；5、除硬单元；6、电解单元；7、蒸发结晶单元；8、冷冻结晶单元；9、双极膜单元；10、产水储罐；11、浓水储罐；12、碱液储罐；13、酸液储罐。
具体实施方式
下面结合具体实施例及附图对本发明作进一步描述。
如图1所述，一种循环冷却水零排污处理系统，该系统包括与循环水系统补水口相连的过滤单元1，和与循环水系统排污口连接的旁滤反洗水降浊单元2，所述的旁滤反洗水降浊单元2依次与高效降浊单元3、分盐单元4相连，其中分盐单元4设有产水出口和浓水出口，分别与产水储罐10和浓水储罐11连接，所述的浓水储罐11与除硬单元5相连，所述除硬单元5设置有与冷冻结晶单元8相连的出液口和盐垢排放出口；所述的产水储罐10的三个出口分别与电解单元6、蒸发结晶单元7、双极膜单元9相连；其中所述的双极膜单元9的酸液出口和碱液出口分别与酸液储罐13和碱液储罐12相连；所述的过滤单元1为微滤或超滤装置，所述的电解单元6的次氯酸钠出液口与循环水系统的加药口相连。
本发明还提供了一种上述处理系统用于循环冷却水零排污处理的方法，该方法包括如下步骤：
1)将污水处理外排水经微滤或超滤装置1处理后作为补水进入循环水系统，循环水系统产生的排污水从排污口排出口进入旁滤反洗水降浊单元2进行降浊处理至产水浊度为50NTU；
2)旁滤反洗水降浊单元2出水进入高效降浊单元3进一步降浊，使产水浊度小于10NTU，产生的污泥排出系统；
3)高效降浊单元3产水进入分盐单元4经分盐处理得到分盐产水和分盐浓水，分别进入产水储罐10和浓水储罐11；
4)产水储罐10中的产水分为三部分，其中大部分产水进入蒸发结晶单元7进行蒸发结晶得到氯化钠，外排或资源化利用；一部分产水进入电解单元6经电解得到次氯酸钠溶液循环回循环水系统加药口；一部分产水进入双极膜单元9电解得到酸液、碱液，作为循环水系统pH调节剂；
5)浓水储罐11的浓水进入除硬单元5进行除硬处理得到盐垢和除硬 后的浓水，除硬后的浓水再进入冷冻结晶单元8经冷冻结晶处理得到水合硫酸钠，外排或资源化利用。
通过本发明方法，循环水系统中的盐份通过循环冷却水塔风吹夹带、高效降浊单元产生的污泥夹带、除硬单元产生的盐垢、蒸发结晶单元产出的氯化钠固体和冷冻结晶单元产出的水合硫酸钠等途径排出系统，以实现系统内的盐份总体平衡，保持循环水含盐量在一定范围内稳定波动。
实施例1：
山西某煤化工企业，现有循环冷却塔1座，循环量200m3/h，系统补水为厂区排污水，经超滤系统过滤后回补循环水系统，补水电导40000～50000us/cm，通过循环水系统进行水质浓缩，循环水电导160000～180000us/cm；循环水系统设置旁滤1套，处理量40m3/h，旁滤反洗水约5m3/h，反洗水经旁滤反洗水降浊单元处理后，浊度降低至40～50NTU，之后进入高效降浊单元，通过在高效降浊单元中投加絮凝剂和助凝剂的方法，使水中的悬浮物形成沉淀，通过污泥压滤设备排出系统；高效降浊单元的出水浊度约10NTU，再进入分盐单元进行处理；分盐单元产生产水和浓水两股水，分别进入产水储罐和浓水储罐。产水储罐中为浓度较高的氯化钠溶液，进入蒸发结晶单元进行蒸发结晶，形成氯化钠固体；蒸发结晶设备的处理量为5～10t/h，采用三效结晶蒸发器，蒸汽耗量约0.5～0.7吨蒸汽/吨水。同时根据水质中异养菌指标及pH变化情况，取部分氯化钠溶液分别通过电解单元和双极膜单元进行处理，其中电解单元可产生3～10g/L的次氯酸钠溶液，用于返回循环水系统进行杀菌及促进COD降解；双极膜单元可产出浓度3～5％的稀酸液和稀碱液，分别存储于稀酸储罐和稀碱储罐，根据需要投加于循环水系统进行系统pH的调节。浓水储罐中为浓度较高的硫酸钠溶液，先进入除硬单元进行钙离子的去除，钙离子去除率为80～90％，形成碳酸钙盐垢以固体形式排出系统；除硬单元出水最终进入冷冻结晶单元处 理，形成水合硫酸钠，以固体形式排出系统，形成硫酸钠的资源化二次利用。系统每日氯化钠和水合硫酸钠产出量约600～900kg。循环水池内挂片腐蚀速率：碳钢片为0.0246mm/a，不锈钢片：0mm/a，满足国家标准相关要求。

Claims (10)

  1. 一种循环冷却水零排污处理系统，其特征在于：包括循环水系统，所述循环水系统包括补水口、排污口和加药口，所述补水口连接过滤单元，所述排污口连接旁滤反洗水降浊单元，所述旁滤反洗水降浊单元依次连接高效降浊单元和分盐单元，所述分盐单元包括分盐浓水出口和分盐产水出口，所述分盐浓水出口连接浓水储罐，所述浓水储罐连接除硬单元，所述除硬单元包括出液口和盐垢排出口，所述出液口连接冷冻结晶单元，所述分盐产水出口连接产水储罐，所述产水储罐包括第一出口、第二出口和第三出口，所述第一出口连接双极膜单元，所述双极膜单元包括酸液出口和碱液出口，所述酸液出口连接酸液储罐，所述碱液出口连接碱液储罐，所述酸液储罐和所述碱液储罐均连接所述加药口，所述第二出口连接蒸发结晶单元，所述第三出口连接电解单元，所述电解单元包括电解出液口，所述电解出液口连接所述加药口。
  2. 根据权利要求1所述的一种循环冷却水零排污处理系统，其特征在于：所述过滤单元和所述旁滤反洗水降浊单元均为微滤装置或超滤装置。
  3. 根据权利要求1或2所述的一种循环冷却水零排污处理系统，其特征在于：所述高效降浊单元设有降浊出水口，所述降浊出水口连接所述补水口，所述高效降浊单元为絮凝沉淀池、高效沉淀池或气浮沉淀池。
  4. 根据权利要1或2所述的一种循环冷却水零排污处理系统，其特征在于：所述除硬单元为电化学除硬单元或化学除硬单元。
  5. 根据权利要求1或2所述的一种循环冷却水零排污处理系统，其特征在于：所述过滤单元、所述旁滤反洗水降浊单元、所述高效降浊单元、所述分盐单元、所述除硬单元、所述冷冻结晶单元、所述双极膜单元、所述蒸发结晶单元、所述电解单元均为撬块化设计。
  6. 一种循环冷却水零排污处理方法，利用上述权利要求1-5任一所述的循环冷却水零排污处理系统，其特征在于：包括以下步骤，
    S1：将污水处理外排水经过滤单元处理后作为补水进入循环水系统，所述循环水系统产生的排污水，经排污口进入旁滤反洗水降浊单元，进行降浊处理至出水浊度为50NTU；
    S2：所述旁滤反洗水降浊单元出水进入高效降浊单元进一步降浊，使出水浊度小于10NTU；
    S3：所述高效降浊单元出水进入分盐单元，经分盐单元处理得到分盐产水和分盐浓水，所述分盐产水进入产水储罐，所述分盐浓水进入浓水储罐；
    S4：所述产水储罐中的分盐产水经三个出口流出，其中大部分分盐产水进入蒸发结晶单元进行蒸发结晶处理，得到固体氯化钠，所述固体氯化钠外排或资源化利用，一部分分盐产水进入电解单元经电解处理，得到次氯酸钠溶液，所述次氯酸钠溶液返回所述循环水系统，一部分分盐产水进入双极膜单元，电解处理得到酸液和碱液，所述酸液和所述碱液作为pH调节剂进入所述循环水系统；
    S5：所述浓水储罐中的分盐浓水进入除硬单元进行除硬处理，得到盐垢和除硬浓水，盐垢外排，同时所述除硬浓水再经冷冻结晶单元处理后，得到水合硫酸钠，所述水合硫酸钠外排或资源化利用。
  7. 根据权利要求6所述的一种循环冷却水零排污处理方法，其特征在于：所述S1中，经所述过滤单元处理后的产水浊度小于0.5NTU。
  8. 根据权利要求6或7所述的一种循环冷却水零排污处理方法，其特征在于：所述S2中的所述高效降浊单元为絮凝沉淀池，投加的絮凝剂或助凝剂为聚合硫酸铁、聚合氯化铝和/或聚丙烯酰胺。
  9. 根据权利要求6或7所述的一种循环冷却水零排污处理方法，其特征在于：所述S3中，所述高效降浊单元出水全部进入分盐单元，或部分进入分盐单元，剩余部分所述高效降浊单元出水作为补水返回所述循环水系统。
  10. 根据权利要求6或7所述的一种循环冷却水零排污处理方法，其特征在于：还包括定期或连续向所述循环水系统中投加50～200ppm的杀菌剂，保持水中余氯浓度维持在0.5～1.0ppm，根据需要定期或连续向系统中投加5～100ppm高效缓蚀阻垢剂，以控制系统的粘附速率和腐蚀速率指标。
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109081488A (zh) * 2018-08-03 2018-12-25 北京朗新明环保科技有限公司 一种工业浓盐水资源化利用的方法及系统
CN110655258A (zh) * 2019-10-16 2020-01-07 百世天蓝(宁夏)环境技术有限公司 一种煤化工高盐废水零排放的新型集成处理系统及工艺
CN113173674A (zh) * 2021-05-24 2021-07-27 陕西省石油化工研究设计院 一种高盐浓水资源化的处理系统及方法
CN113461236A (zh) * 2021-07-27 2021-10-01 江苏海容热能环境工程有限公司 一种电厂高盐废水分质处理的零排放系统
CN114772822A (zh) * 2022-03-14 2022-07-22 天津正达科技有限责任公司 一种循环冷却水零排污处理系统及方法

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN217677157U (zh) * 2022-03-14 2022-10-28 天津正达科技有限责任公司 一种循环冷却水零排污处理系统

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109081488A (zh) * 2018-08-03 2018-12-25 北京朗新明环保科技有限公司 一种工业浓盐水资源化利用的方法及系统
CN110655258A (zh) * 2019-10-16 2020-01-07 百世天蓝(宁夏)环境技术有限公司 一种煤化工高盐废水零排放的新型集成处理系统及工艺
CN113173674A (zh) * 2021-05-24 2021-07-27 陕西省石油化工研究设计院 一种高盐浓水资源化的处理系统及方法
CN113461236A (zh) * 2021-07-27 2021-10-01 江苏海容热能环境工程有限公司 一种电厂高盐废水分质处理的零排放系统
CN114772822A (zh) * 2022-03-14 2022-07-22 天津正达科技有限责任公司 一种循环冷却水零排污处理系统及方法

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