CN117682717B

CN117682717B - Supercritical water-based high-salinity wastewater circulating treatment method and system

Info

Publication number: CN117682717B
Application number: CN202410020391.7A
Authority: CN
Inventors: 黎锋; 黄炫杰; 毕永锐; 蔡耿林; 张乃元
Original assignee: Individual
Current assignee: Individual
Filing date: 2024-01-05
Publication date: 2024-06-07
Anticipated expiration: 2044-01-05

Abstract

The invention relates to the technical field of sewage treatment, and particularly discloses a supercritical water-based high-salinity wastewater recycling treatment method and a supercritical water-based high-salinity wastewater recycling treatment system, wherein the method comprises the following steps of: s1, heating and evaporating high-salt wastewater flowing into a crystallizer to obtain pretreated wastewater, wherein the pretreated wastewater is high-salt wastewater with crystals; s2, carrying out solid-liquid separation on the pretreated wastewater, separating the pretreated wastewater by adopting a centrifugal separator, separating out crystal salt, and obtaining high-concentration mother liquor; s3, performing supercritical water oxidation treatment on the high-concentration mother liquor, and converting organic matters in the high-concentration mother liquor into carbon dioxide, nitrogen and water through chemical reaction; s4, conveying the liquid wastewater into the crystallizer, performing step S1 with the high-salt wastewater input subsequently, and treating the high-salt wastewater by using a supercritical water oxidation method to degrade organic matters into harmless nitrogen oxides and carbon oxides, and performing cyclic evaporation crystallization, so that zero emission of industrial wastewater can be achieved, and dangerous waste of mother liquor sludge is prevented.

Description

Supercritical water-based high-salinity wastewater circulating treatment method and system

Technical Field

The invention relates to the technical field of sewage treatment, in particular to a supercritical water-based high-salinity wastewater recycling treatment method and a supercritical water-based high-salinity wastewater recycling treatment system.

Background

The high-salt wastewater refers to wastewater with the total salt content of at least 1% by mass, which is mainly from chemical plants, petroleum and natural gas collection and processing and the like, and contains various substances (including salt, oil, organic heavy metals and radioactive substances), the organic pollutants in the salt wastewater can influence the environment, and the high-concentration salt substances have an inhibition effect on microorganisms, and direct discharge can directly pollute the living environment; the high-salt wastewater is often accompanied by high-content organic matters, namely organic matters containing carbohydrates, proteins, grease, lignin and the like, which exist in suspended or dissolved state in the wastewater and can be decomposed by the biochemical action of microorganisms, and oxygen is consumed in the decomposition process, so that the high-salt wastewater is called oxygen-consuming pollutant, and the pollutant can cause reduction of dissolved oxygen in the water and influence the growth of fish and other aquatic organisms.

At present, the traditional high-salt wastewater treatment methods comprise a distillation desalination method, a biochemical treatment method and the like, but the types and chemical properties of organic matters contained in the high-salt organic wastewater are greatly different according to different production processes, wherein the main salt-containing matters are mainly chloride ions Cl-, sulfate ions SO42-, sodium ions Na+, calcium ions Ca2+ and other salt-containing matters; the distillation desalination method is the oldest and most commonly used desalination method, and the distillation desalination technology is developed basically on the basis of the sea water desalination technology, and the distillation method is a process of heating salt-containing water to boil and evaporate the salt-containing water and condensing steam into fresh water, but has high treatment cost and is not beneficial to popularization and use.

If the biochemical treatment method is adopted to treat the high-salt wastewater, as the main salt substances such as chloride ions Cl-, sulfate ions SO42-, sodium ions Na+, calcium ions Ca2+ and the like are all nutrient elements necessary for the growth of microorganisms, the biochemical treatment method plays a role in promoting enzyme reaction in the growth process of the microorganisms, and can maintain the membrane balance of the microorganisms and regulate osmotic pressure; however, if these ion concentrations are too high, inhibition and poisoning of the microorganisms may occur, which mainly is: the salt concentration is high, the osmotic pressure is high, and the cell plasma separation is caused by the dehydration of the microbial cells, so that the biochemical treatment method adopted by the microbial cell plasma separation is disabled; in addition, due to the salting-out effect, the activity of dehydrogenase can be reduced, and the high chloride ion has toxic effect on bacteria, and the high concentration salt can cause the increase of the density of wastewater, the activated sludge is easy to float and run off, so that the purification effect of a biological treatment system is seriously affected; therefore, the biochemical treatment method cannot effectively improve the treatment efficiency of the high-salt wastewater, and cannot treat the high-concentration high-salt wastewater, so that the application range of the high-salt wastewater is greatly reduced.

For example, the patent name of the Chinese invention patent with the publication number of CN114195313A is a "near zero discharge treatment method of circulating water sewage", and the technical scheme disclosed by the Chinese invention patent is as follows: firstly, pretreating drainage by adopting a pretreatment process, and then concentrating by adopting a reverse osmosis process to obtain fresh water and concentrated water; deep treatment is carried out on the obtained concentrated water, so that the treatment capacity of the subsequent concentrated water is reduced, and the fresh water reaches the recycling standard of the circulating water supplementing water; and (3) carrying out evaporative crystallization treatment on the concentrated water after reduction to obtain evaporative condensate water for recycling and solid crystallization outward transportation treatment. The method utilizes a reverse osmosis method to recycle a large amount of circulating water to the whole system more economically, then carries out high-pressure reverse osmosis membrane concentration after hardness removal of concentrated water, greatly reduces the water quantity of subsequent treatment, greatly improves the water utilization rate, carries out evaporation treatment again after the concentrated water is recycled to the circulating water system, carries out solid crystallization outward, and maximally realizes recycling of the circulating water to the sewage.

Therefore, how to carry out purification treatment on high-salt wastewater with different concentrations is a technical problem which needs to be solved by the current technicians.

Disclosure of Invention

The invention aims to provide a supercritical water-based high-salinity wastewater recycling treatment method and a supercritical water-based high-salinity wastewater recycling treatment system, which solve the problems in the prior art.

In order to achieve the above purpose, the present invention provides the following technical solutions:

The application provides a supercritical water-based high-salinity wastewater recycling treatment method, which comprises the following steps of:

s1, heating and evaporating high-salt wastewater flowing into a crystallizer to obtain pretreated wastewater, wherein the pretreated wastewater is high-salt wastewater with crystals;

s2, carrying out solid-liquid separation on the pretreated wastewater, separating the pretreated wastewater by adopting a centrifugal separator, separating out crystal salt, and obtaining high-concentration mother liquor;

S3, placing the high-concentration mother liquor into an inner cavity of a reactor, performing supercritical water oxidation treatment on the high-concentration mother liquor, adding oxygen into the inner cavity of the reactor when the high-concentration mother liquor reaches a supercritical water state, and converting organic matters in the high-concentration mother liquor into carbon dioxide, nitrogen and water through chemical reaction to obtain liquid wastewater and high-temperature gas;

S4, conveying the liquid wastewater into the crystallizer, and executing the step S1 with the high-salt wastewater input subsequently.

Preferably, in the step S3, when the high-concentration mother liquor reaches a supercritical state, the temperature value of the high-concentration mother liquor is greater than 374 ℃, and the pressure value of the high-concentration mother liquor is greater than 22.1MPa.

Preferably, in the step S1, the evaporation temperature is 100 ℃ to 120 ℃, and the evaporation time period is 30Min to 45Min.

Preferably, in the step S3, the high-concentration mother liquor exchanges heat with supercritical water in the inner cavity of the reactor to cool the high-concentration mother liquor before entering the inner cavity of the reactor.

Preferably, in the step S4, before the high-concentration mother liquor enters the inner cavity of the reactor, the high-concentration mother liquor exchanges heat with the liquid wastewater to obtain high-temperature high-concentration mother liquor.

Preferably, the temperature of the high-temperature concentrated solution is smaller than the temperature of the high-temperature gas, the high-temperature concentrated solution exchanges heat with the high-temperature gas to raise the temperature, and the high-temperature concentrated solution after the temperature rise enters the inner cavity of the reactor to execute the step S3.

Preferably, in the step S3, the oxygen amount is proportionally added according to the supercritical water chemical oxygen demand of the inner cavity of the reactor.

In a second aspect, the present application provides a high-salinity wastewater recycling system, comprising: the device comprises a mother liquor collector, a reactor, a jacket, a buffer tank, a material heat exchanger and a gas heat exchanger;

the buffer tank is used for carrying out high Wen Nongye liquid supply to the inner cavity of the reactor, the outer wall of the reactor is provided with a jacket, the mother liquor collector is used for carrying out high-concentration mother liquor supply to the inner cavity of the jacket, a heater used for heating is arranged in the reactor, when the inner cavity high-concentration mother liquor of the reactor is heated to a supercritical water state, oxygen is added into the inner cavity of the reactor to obtain liquid wastewater and high-temperature gas, the inner cavity high-concentration mother liquor of the jacket is used for carrying out heat exchange and cooling on supercritical water in the reactor, the liquid wastewater in the inner cavity of the reactor and the high-concentration mother liquor of the jacket are all discharged into the material heat exchanger, the material heat exchanger is used for carrying out heat exchange on the liquid wastewater and the high-concentration mother liquor, the high Wen Nongye is obtained after the high-concentration mother liquor exchanges heat with the liquid wastewater, the inner cavity high-temperature gas of the reactor is discharged to the gas heat exchanger, the gas heat exchanger is used for carrying out heat exchange on the high-temperature gas and the high-temperature concentrated liquor, and the gas heat exchanger is communicated with the buffer tank.

Preferably, a high-pressure pump is arranged at the liquid outlet of the mother liquor collector, and a discharge pump is arranged at the liquid outlet of the reactor.

Preferably, the liquid wastewater of the material heat exchanger is discharged into a crystallizer for cyclic crystallization, and the high-temperature gas of the gas heat exchanger is directly discharged after heat exchange.

Compared with the prior art, the invention provides a supercritical water-based high-salinity wastewater recycling treatment method and a supercritical water-based high-salinity wastewater recycling treatment system, which have the beneficial effects that: the high-salt wastewater is evaporated and crystallized through a crystallizer and then separated through a centrifugal separator to obtain crystallized salt and high-concentration mother liquor, the high-concentration mother liquor is discharged into a mother liquor collector for concentrated storage, the high-concentration mother liquor is discharged into a jacket of the reactor after being pressurized by a high-pressure pump through the mother liquor collector, heat exchange and cooling are carried out on high-temperature and high-pressure high Wen Nongye which is oxidized in the reactor, supercritical water in the reactor is recovered to a liquid state after heat exchange and cooling and depressurization to obtain liquid wastewater, the high-concentration mother liquor in the jacket and the liquid wastewater enter a heat exchanger for liquid-liquid heat exchange at the same time, thereby the high-concentration mother liquor is heated to obtain high Wen Nongye, the heated high Wen Nongye enters a gas exchanger for heat exchange with high-temperature gas discharged from an inner cavity of the reactor, the high Wen Nongye after heat exchange and the temperature rise enters a buffer tank, after the liquid wastewater in the reactor is completely discharged, high Wen Nongye in the buffer tank is discharged into the reactor, high Wen Nongye is continuously heated and pressurized by a heater in the reactor, when the temperature and the pressure are both over 374 ℃ and 22.1MPa, high-temperature concentrated solution can reach a supercritical state, at the moment, oxygen is added into the reactor, a supercritical water oxidation technology is utilized for chemical reaction, organic matters in the high Wen Nongye are quickly converted into carbon dioxide, water and nitrogen, after the reaction is finished, the supercritical water in the reactor is cooled and depressurized by high-concentration mother liquor in a jacket, the high Wen Nongye in the reactor is recovered into liquid wastewater in a liquid state, the liquid wastewater is discharged into a crystallizer by a discharge pump to be evaporated and crystallized together with high-salt wastewater, thus realizing cyclic evaporation and crystallization work, high-temperature gas is discharged, such cycle can achieve zero discharge of industrial wastewater, and the generation of dangerous waste of mother liquor sludge is prevented.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of an overall process flow provided by an embodiment of the present application.

Fig. 2 is a schematic diagram of a high-salt wastewater recycling treatment system provided by an embodiment of the application.

FIG. 3 is a flow chart of a method for circularly treating high-salinity wastewater based on supercritical water according to an embodiment of the application

Detailed Description

Preferred embodiments of the present application will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present application have been illustrated in the drawings, it should be understood that the present application may be embodied in various forms and should not be limited to the embodiments set forth herein, but rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

In the description of the present application, it should be understood that the terms "thickness," "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present application; furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated; thus, the definition of "first", "second" is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly including one or more such features.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

The following describes the technical scheme of the embodiment of the present application in detail with reference to the accompanying drawings.

Referring to fig. 1 to 2, a supercritical water-based high-salinity wastewater recycling treatment method includes the steps of:

Specifically, in the step S3, when the high-concentration mother liquor reaches a supercritical state, the temperature value of the high-concentration mother liquor is greater than 374 ℃, and the pressure value of the high-concentration mother liquor is greater than 22.1MPa.

Specifically, in the step S1, the evaporation temperature is 100-120 ℃, and the evaporation time period is 30-45 Min.

Specifically, in the step S3, before the high-concentration mother solution enters the inner cavity of the reactor, the high-concentration mother solution exchanges heat with supercritical water in the inner cavity of the reactor to cool.

Specifically, in the step S4, before the high-concentration mother liquor enters the inner cavity of the reactor, the high-concentration mother liquor exchanges heat with the liquid wastewater to obtain a high Wen Nongye.

Specifically, the temperature of the high-temperature concentrated solution is smaller than that of the high-temperature gas, the high-temperature concentrated solution and the high-temperature gas exchange heat and raise temperature, and the high-temperature concentrated solution after the temperature rise enters the inner cavity of the reactor to execute the step S3.

Specifically, in the step S3, the oxygen amount is proportionally added according to the supercritical water chemical oxygen demand of the inner cavity of the reactor.

Specifically, the liquid outlet of mother liquor collector is installed and is had the high-pressure pump, the discharge pump is installed to the liquid outlet of reactor.

Specifically, the liquid wastewater of the material heat exchanger is discharged into a crystallizer for cyclic crystallization, and the high-temperature gas of the gas heat exchanger is directly discharged after heat exchange.

Example 1

In the zero emission treatment process of high-salt wastewater, the evaporation crystallization process often cannot completely realize zero emission of industrial wastewater due to the existence of organic matters, because supersaturated crystal salt is separated out of a system in the separation process of a centrifugal device, and separated mother liquor returns to an evaporation system to be evaporated and concentrated continuously, wherein the mother liquor is saturated solution which is remained after precipitation or crystals are separated out in the chemical precipitation or crystallization process, and the organic matters are dissolved in the mother liquor and are not carried out of the system along with the crystal salt, so that the concentration of the organic matters in the evaporation system is higher and higher along with the time until foaming is serious in the evaporation process and the evaporation efficiency is seriously reduced; the crystallization particles are small and can not be separated from solid and liquid, and hardening and other phenomena occur in the evaporator.

In order to solve the above problems, the conventional treatment method is as follows: when the concentration and enrichment of organic matters in an evaporation system are to a certain degree, and the normal evaporation of the evaporation system cannot be influenced, mother liquor in the system is required to be discharged and treated independently, however, as the mother liquor belongs to high-salt high-organic matters, the conventional chemical method and biological method do not have an economic and effective treatment method at present, particularly for wastewater with the organic matter content of more than 50 ten thousand ppm, the current common mode is to carry out high-temperature drying treatment on the mother liquor through a sludge dryer under the condition, and mother liquor sludge generated by the method is generally dangerous waste.

In order to prevent the situation of mother liquor sludge in the process of high-temperature drying treatment of high-concentration mother liquor organic matters, please refer to fig. 1 and 3, the technical scheme includes: a high-salinity wastewater recycling treatment method based on supercritical water comprises the following steps:

S3, placing the high-concentration mother liquor into an inner cavity of a reactor, performing supercritical water oxidation treatment on the high-concentration mother liquor, and when the high-concentration mother liquor reaches a supercritical water state, setting the temperature value of the high-concentration mother liquor to be more than 374 ℃, setting the pressure value of the high-concentration mother liquor to be more than 22.1MPa, adding oxygen into the inner cavity of the reactor, and converting organic matters in the high-concentration mother liquor into carbon dioxide, nitrogen and water through chemical reaction to obtain liquid wastewater and high-temperature gas, wherein the high-temperature gas is carbon oxide gas and nitrogen oxide gas;

In S2, the centrifugal separator is a machine for separating each component in the mixture of the liquid and the solid particles or the liquid and the liquid by using centrifugal force, and is also called a tube type centrifuge. Centrifugal separators are mainly used to separate solid particles from liquids in suspension; or separating two liquids of different densities from each other in the emulsion (e.g., separating cream, oil, and water from milk); it can also be used to remove liquids from wet solids.

In S1, the whole set of evaporation system consists of two groups of forced circulation crystallizers, the two groups of crystallizers are operated in series to jointly form a triple-effect crystallizer, and the evaporation system adopts a production mode of continuous feeding and continuous discharging. In the step S1, the sewage stock solution enters a one-effect forced circulation crystallizer, the crystallizer is provided with a forced circulation pump, the liquid is pumped into an evaporation heat exchange chamber, the external steam is used for heating the stock solution in the evaporation heat exchange chamber, the pressure in the evaporation heat exchange chamber is large, the liquid is heated to overheat in the evaporation heat exchange chamber under the pressure higher than the normal boiling point of the liquid, the evaporation temperature is 100-120 ℃ in the evaporation crystallization process, and the evaporation time is 30-45 Min.

After the heated liquid enters the crystallization evaporation chamber, the pressure of the liquid drops rapidly, which causes a part of the liquid to flash or boil rapidly. The vapor after the liquid evaporation enters a two-effect crystallization evaporator to be heated, and the non-evaporated liquid and salt are temporarily stored in a crystallization evaporation chamber. The waste water is evaporated continuously, the salt concentration in the waste water is higher and higher, and when the salt in the waste water exceeds the saturation state, the salt in the water is separated out continuously and enters a salt collecting chamber at the lower part of the evaporation crystallization chamber. The circulating pump continuously sends the wastewater containing salt to the centrifugal separator, in the centrifugal separator, solid salt is separated into a salt storage pool, liquid enters the heating chamber for heating, and the whole process is repeated to realize the separation of water and salt.

As further described in the above examples, supercritical water oxidation (Supercritical Water Oxidation, SCWO) is a technology that can achieve advanced oxidation treatment of various organic wastes, in which the supercritical water oxidation is to completely oxidize organic matters into clean substances such as H2O, CO2 and N2 by oxidation, and S, P is to stabilize the substances by converting them into the highest-valence salts, and the heavy metal oxidation stable solid phase exists in ash. The supercritical water oxidation (Supercritical Water Oxidation, SCWO) technology is based on the principle that supercritical water is used as a reaction medium, and organic matters are rapidly converted into carbon dioxide, water and nitrogen through homogeneous oxidation reaction.

When the temperature and pressure of the system exceed the critical point, the supercritical water refers to water with the density of water expanded at high temperature and the density of water vapor compressed at high pressure being exactly the same when the air pressure and the temperature reach a certain value, and at the moment, the liquid and the gas of the water are completely mixed together without distinction, so that a new fluid with high pressure and high temperature state is formed. Supercritical water has two significant characteristics: one of them is to have strong reactivity, and the substances to be treated are put into supercritical water, and oxygen and hydrogen peroxide are filled, so that the substances are oxidized and hydrolyzed. Some also self-ignition occurs, which fires in water. Another characteristic is that it can be mixed with substances such as oil and the like, and has a wider fusion ability.

In summary, it is obtained that the pretreatment wastewater is obtained after the high-salt wastewater is evaporated and crystallized through the crystallizer, solid-liquid separation is performed on the pretreatment wastewater through the centrifugal separator to obtain crystalline salt and high-concentration mother liquor, the obtained high-concentration mother liquor is discharged into the mother liquor collector, the inner cavity of the reactor is industrially treated through the mother liquor collector, oxygen is injected after the high-concentration mother liquor is heated to reach a supercritical state, organic matters are removed from the high-concentration mother liquor through a supercritical water oxidation technology, then solid-liquid separation is performed to obtain liquid wastewater and high-temperature gas, wherein the liquid wastewater is discharged into the crystallizer and evaporated and crystallized together with the high-concentration brine, and the liquid wastewater and the high-temperature gas are sequentially circulated, the technical scheme effectively obtains liquid wastewater and high-temperature gas through the evaporation and crystallization after the organic matters in the high-salt wastewater are removed, so that the effect of zero-discharge of industrial sewage is realized, the concentration of the organic matters can be higher and higher along with the time in the evaporation and crystallization process is prevented, and the evaporation efficiency is seriously reduced until the evaporation process occurs; the crystallization particles are small and can not be separated from solid and liquid, and hardening and other phenomena occur in the evaporator.

Example two

Because organic matters exist, the evaporation crystallization process often cannot realize zero discharge of sewage, because supersaturated crystal salt is separated out of the system in the process of separation by a centrifuge, and separated mother liquor returns to the evaporation system to continue evaporation concentration, and the organic matters are dissolved in the mother liquor and are not carried out of the system along with the crystal salt, so that the concentration of the organic matters in the evaporation system can be higher and higher along with the time until serious foaming in the evaporation process occurs, and the evaporation efficiency is seriously reduced; the crystallization particles are small and can not be separated from solid and liquid, and are hardened in the evaporator (the same as above).

The application can avoid the generation of dangerous waste of mother liquor sludge by using a supercritical water-based high-salt wastewater circulation treatment method, and degrade organic matters in the mother liquor into harmless nitrogen or/and carbon oxides and then discharge the harmless nitrogen or/and carbon oxides, but waste heat loss generated in the circulation process easily causes waste heat waste, and the treatment cost is increased, so that the waste heat is needed to be utilized in the circulation process, and referring to fig. 1 to 2, the technical scheme comprises the following steps: the device comprises a mother liquor collector, a reactor, a jacket, a buffer tank, a material heat exchanger and a gas heat exchanger;

The buffer tank is used for supplying liquid to the inner cavity of the reactor by high Wen Nongye, the outer wall of the reactor is provided with a jacket, the mother liquor collector is used for supplying liquid to the inner cavity of the jacket, a heater used for heating is arranged in the reactor, when the inner cavity of the reactor is heated to a supercritical water state, oxygen is added into the inner cavity of the reactor to obtain liquid wastewater and high-temperature gas, wherein the high-temperature gas is carbon oxide gas and nitrogen oxide gas, the inner cavity of the jacket is used for carrying out heat exchange and cooling on the supercritical water in the reactor, the liquid wastewater in the inner cavity of the reactor and the high-concentration mother liquor of the jacket are all discharged into the material heat exchanger, the material heat exchanger is used for carrying out heat exchange on the liquid wastewater and the high-concentration mother liquor, the high Wen Nongye is obtained after the high-concentration mother liquor and the liquid wastewater are subjected to heat exchange, the inner cavity high-temperature gas of the reactor is discharged into the gas heat exchanger, the gas heat exchanger is used for carrying out heat exchange on the high-temperature gas and the high Wen Nongye, and the gas heat exchanger is communicated with the buffer tank.

For the above description, further limitation is made that a high-pressure pump is installed at the liquid outlet of the mother liquor collector, and a discharge pump is installed at the liquid outlet of the reactor.

For the above description, the method is further defined that the liquid waste water of the material heat exchanger is discharged into the crystallizer for cyclic crystallization, and the high-temperature gas of the gas heat exchanger is directly discharged after heat exchange.

In summary, the mother liquor collector discharges the high-concentration mother liquor into the jacket of the reactor after being pressurized by the high-pressure pump, the heat exchange and the temperature reduction are carried out on the high-temperature high-pressure Wen Nongye which is completed in the reactor, supercritical water in the reactor is subjected to heat exchange, temperature reduction and pressure reduction, then the supercritical water in the reactor is recovered to a liquid state to obtain liquid wastewater, the high-concentration mother liquor in the jacket and the liquid wastewater simultaneously enter the heat exchanger to carry out liquid-liquid heat exchange, so that the high-concentration mother liquor is heated to obtain high Wen Nongye, the heated high Wen Nongye enters the gas exchanger and exchanges heat with high-temperature gas discharged from the inner cavity of the reactor, the high Wen Nongye after heat exchange and temperature increase enters the buffer tank, after the liquid wastewater in the reactor is completely discharged, the high Wen Nongye in the buffer tank is discharged into the reactor, the high Wen Nongye is heated and pressurized continuously by the heater in the reactor, when the temperature and the pressure are both exceed 374 ℃ and 22.1MPa, oxygen is added into the reactor at the moment, and organic matters in the high Wen Nongye are rapidly converted into carbon dioxide, water and nitrogen by the supercritical oxidation technology. After the reaction is finished, supercritical water in the reactor is cooled and depressurized through high-concentration mother liquor in the jacket, so that the high Wen Nongye in the reactor is recovered to liquid wastewater in a liquid state, the liquid wastewater is discharged through a discharge pump, and high-temperature gas is discharged, and the circulation is performed.

According to the above embodiment, in order to further supplement the above embodiment, in order to prevent the temperature in the reactor from being too high, a temperature detector can be installed in the reactor to detect the temperature, after the temperature is detected, a switch of the heater is controlled by the sensor, so that the heater is turned off when the temperature in the reactor reaches a preset value, wherein in order to prevent the buffer tank from injecting high-temperature concentrated liquid when the reactor does not completely discharge liquid waste water, the problem that the liquid waste water and the high Wen Nongye are mixed after the reaction in the reactor is completed occurs, a control valve switch can be installed at a liquid outlet of the buffer to control the high Wen Nongye of the buffer tank to be discharged into the inner cavity of the reactor.

The aspects of the present application have been described in detail hereinabove with reference to the accompanying drawings. In the foregoing embodiments, the descriptions of the embodiments are focused on, and for those portions of one embodiment that are not described in detail, reference may be made to the related descriptions of other embodiments. Those skilled in the art will also appreciate that the acts and modules referred to in the specification are not necessarily required for the present application. In addition, it can be understood that the steps in the method of the embodiment of the present application may be sequentially adjusted, combined and pruned according to actual needs, and the modules in the device of the embodiment of the present application may be combined, divided and pruned according to actual needs.

The foregoing description of embodiments of the application has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described. The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application, or the improvement of technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. The high-salt wastewater recycling treatment method based on supercritical water is executed by adopting a high-salt wastewater recycling treatment system and is characterized by comprising the following steps of:

s4, conveying the liquid wastewater into a crystallizer, and executing the step S1 together with the high-salt wastewater input subsequently;

The high-salt wastewater recycling treatment system comprises:

the device comprises a mother liquor collector, a reactor, a jacket, a buffer tank, a material heat exchanger and a gas heat exchanger;

The buffer tank is used for supplying high Wen Nongye liquid to the inner cavity of the reactor, the outer wall of the reactor is provided with a jacket, the mother liquor collector is used for supplying high-concentration mother liquor to the inner cavity of the jacket, a heater used for heating is arranged in the reactor, when the inner cavity high-concentration mother liquor of the reactor is heated to a supercritical water state, oxygen is added into the inner cavity of the reactor to obtain liquid wastewater and high-temperature gas, the inner cavity high-concentration mother liquor of the jacket is used for carrying out heat exchange and cooling on the supercritical water in the reactor, the liquid wastewater in the inner cavity of the reactor and the high-concentration mother liquor of the jacket are both discharged into the material heat exchanger, the material heat exchanger is used for carrying out heat exchange on the liquid wastewater and the high-concentration mother liquor, the high Wen Nongye is obtained after the high-concentration mother liquor exchanges heat with the liquid wastewater, the inner cavity high-temperature gas of the reactor is discharged to the gas heat exchanger, the gas heat exchanger is used for carrying out heat exchange on the high-temperature gas and the high-temperature concentrated liquor, and the gas heat exchanger is communicated with the buffer tank; a high-pressure pump is arranged at the liquid outlet of the mother liquor collector, and a discharge pump is arranged at the liquid outlet of the reactor; and the liquid wastewater of the material heat exchanger is discharged into a crystallizer for cyclic crystallization, and the high-temperature gas of the gas heat exchanger is directly discharged after heat exchange.

2. The method for circulating treatment of high-salinity wastewater based on supercritical water according to claim 1, wherein in the step S3, when the high-concentration mother liquor reaches a supercritical state, the temperature value of the high-concentration mother liquor is greater than 374 ℃, and the pressure value of the high-concentration mother liquor is greater than 22.1MPa.

3. The method for circulating treatment of high-salt wastewater based on supercritical water according to claim 1, wherein in the step S1, the evaporation temperature is 100 ℃ to 120 ℃ and the evaporation time period is 30Min to 45Min.

4. The supercritical water-based high-salinity wastewater recycling treatment method according to claim 1, wherein in the step S3, the high-concentration mother liquor exchanges heat with and cools the supercritical water in the inner cavity of the reactor before entering the inner cavity of the reactor.

5. A method of recycling high-salinity wastewater based on supercritical water according to any one of claims 1 to 3, wherein in S4, the high-concentration mother liquor exchanges heat with the liquid wastewater to obtain a high Wen Nongye before entering the inner cavity of the reactor.

6. The supercritical water-based high-salinity wastewater recycling method according to claim 5, wherein the temperature of the high-temperature concentrated solution is smaller than that of the high-temperature gas, the high-temperature concentrated solution and the high-temperature gas exchange heat and raise temperature, and the high-temperature concentrated solution after the temperature rise enters an inner cavity of a reactor to execute step S3.

7. The method for circulating treatment of high-salinity wastewater based on supercritical water according to claim 1, wherein in S3, oxygen is added proportionally according to the chemical oxygen demand of supercritical water in the inner cavity of the reactor.