CN205398323U - Device of high ammonia -nitrogen concentration wastewater resource zero release processing of membrane aeration and membrane absorption coupling technology - Google Patents

Abstract

The invention relates to a device for zero-discharge treatment of high-ammonia-nitrogen wastewater resourced by a coupling process of membrane aeration and membrane absorption, which belongs to the field of environmental engineering. First, the membrane aeration method is used to remove about 60% of the ammonia nitrogen in the ammonia nitrogen wastewater, and then the remaining 99% of the ammonia nitrogen in the wastewater is removed by the membrane absorption multi-stage deamination method, so that the raw water with high ammonia nitrogen can be directly discharged after treatment. The ammonia gas separated in the membrane aeration system is directly passed into the absorption liquid tank during the membrane absorption process to react the excess acid in the absorption liquid tank. Then pass the treated absorption liquid into the by-product recovery system to treat the high-concentration absorption liquid. When the operating capacity is reduced to 70% of the original processing capacity, or when it needs to be shut down for a long time, the cleaning-air washing system needs to be turned on to maintain and clean the system to maintain the long-term stable operation of the system.

Description

A zero-discharge treatment device for high ammonia nitrogen wastewater resource utilization by a membrane aeration and membrane absorption coupling process

technical field

The utility model belongs to the field of environmental engineering, and relates to the technology of recycling ammonia-containing wastewater, in particular to a device for zero-discharge treatment of industrial high-ammonia-nitrogen wastewater using a coupling process of membrane aeration and membrane absorption.

Background technique

my country is seriously short of water resources, and the per capita fresh water resources are only a quarter of the world's average level. The main rivers, lakes and groundwater in the country are polluted to varying degrees, and the pollution is still intensifying. According to monitoring by the environmental protection department, ammonia nitrogen is one of the main pollutants. The main harm of ammonia nitrogen to the environment is that after entering the water body, it becomes a nutrient element for algae and other organisms, causing toxic organisms in the water body to multiply in a short period of time, and at the same time consumes dissolved oxygen in the water, resulting in so-called red tide or eutrophication, which seriously threatens fish and shrimp. life safety and human and animal health. In addition, ammonia nitrogen in water can be converted into nitrite under certain conditions. If consumed for a long time, nitrite in water will combine with protein to form nitrosamine, which is a strong carcinogen and extremely harmful to human health. In recent years, the resulting sudden environmental pollution accidents have occurred from time to time, seriously affecting the sustainable development of our society.

Ammonia-containing wastewater discharged from industrial processes is a major point source that pollutes water bodies and increases the concentration of ammonia nitrogen in water bodies. Compared with the restoration of ammonia nitrogen pollution at the level of rivers and lakes, reducing ammonia nitrogen production from the production source, improving the ammonia recycling rate in the production process, and improving the ammonia nitrogen removal efficiency of enterprise sewage treatment plants can not only greatly reduce pollution control costs, Moreover, it can reduce the consumption of ammonia resources, which is the main means to prevent further deterioration of ammonia nitrogen pollution in rivers, lakes and seas in my country at this stage.

High ammonia nitrogen wastewater comes from a wide range of sources, such as coal chemical wastewater, coking wastewater, petrochemical wastewater, chemical wastewater, landfill leachate, etc. The annual discharge of coking wastewater alone exceeds 180 million tons. Considering other industries, it is conservatively estimated that the overall water volume is about 200 million tons. More than 10,000 tons/day. Due to the high content of ammonia nitrogen in the wastewater of the above industries, generally 1000-10000mg/L, it is difficult to remove it by biological methods, and it needs to be deammonized separately.

As the current high ammonia nitrogen treatment processes mainly include stripping method, ammonia distillation method, and magnesium ammonium phosphate precipitation method. More than 70% of the deammonization process adopts the ammonia distillation method, but the ammonia distillation method has the disadvantages of high energy consumption, high treatment cost (about 25 yuan/ton), serious scaling of equipment, etc., and the magnesium ammonium phosphate precipitation method has the disadvantage of a large amount of sediment , so there is an urgent need to develop cost-effective new high-ammonia nitrogen treatment and recovery technologies and equipment.

As a new type of sewage treatment technology, membrane absorption technology has the characteristics of normal temperature and pressure operation, low energy consumption, small footprint, and removal efficiency of over 95%. At the same time, it can recover ammonia nitrogen resources, which is in line with the concept of circular economy. Membrane absorption is a new separation technology that combines membrane-based gas separation with traditional physical adsorption, chemical absorption, and cryogenic distillation. Compared with traditional absorption technologies, membrane absorption has attracted much attention because of its large gas-liquid contact area, fast mass transfer rate, no mist entrainment, and mild operating conditions.

However, the membrane absorption process currently has the following problems that must be solved in industrial applications. One is the problem of hydrophilization of the membrane module; The concentration is low and the pH value is low, so it cannot be directly used as fertilizer, and the "evaporation-crystallization" salt production technology has the problem of high treatment cost; the third is that the waste liquid with high ammonia nitrogen is recycled instead of continuous Operation will bring many problems such as increased floor area and construction cost, long operation time, and high energy consumption. There are many restrictions in industrial applications, which is not conducive to large-scale industrial applications; The problem of the volume expansion of the absorption liquid caused by the osmotic distillation of the water on the high ammonia nitrogen raw liquid side caused by the poor activity.

The authorized announcement number is CN103086453B "A Method for Ammonia Nitrogen Wastewater Membrane Deamination" invention patent and the authorized announcement number applied at the same time is CN203065287U "A Ammonia Nitrogen Wastewater Membrane Integrated Deamination Device" utility model patent, using vacuum deamination Coupling with membrane absorption process to treat high ammonia nitrogen wastewater, the existing problem is that the cost of vacuum deamination system is high and the process requirements are complicated. In addition, the vacuum deamination system is a static system, and the single-step residence time is 2-5 hours. Subsequent membrane absorption The deammonization system is a cyclic deammonization system, and the treatment time is 1-3 hours. Because the treatment time is too slow, large-scale industrial water treatment systems require a large footprint, and the prospect of industrial practical application is very small.

The invention patent with application number 201510364101.1 proposed "submerged membrane absorption device and deamination method", and the invention patent with application number 201410318014.8 proposed "a submerged, baffled, closed-type hydrophobic membrane continuous ammonia nitrogen removal process 》, the two patents both adopt the submerged deammonization treatment method, which saves land at the cost of reducing the total ammonia nitrogen absorption rate, and does not fully reflect the true value of the membrane absorption process. In addition, the treatment method of submerged membrane absorption is not conducive to the periodic cleaning and drying of the membrane module to keep the hydrophobic membrane module in good operation for a long time and prevent the module from being hydrophilized.

Application No. 201310535302.4 "A Zero Discharge Method for High Salt and High Ammonia Nitrogen Wastewater" invention patent and its simultaneous application No. 201310535284.X "A Zero Discharge Device for High Salt and High Ammonia Nitrogen Wastewater", and the application No. 201310349390.9 "A Process for Treating High-Ammonia Radioactive Wastewater by Membrane Absorption Method" avoids by-products such as ammonium sulfate and ammonium chloride obtained by membrane absorption and deamination. Due to low concentration and low pH value, it cannot be directly used as Fertilizers are used, and the "evaporation-crystallization" salt production technology has the problem of high processing costs.

To sum up, the hydrophilization of membrane modules, the treatment of absorption liquid, and the batch cycle operation mode are still bottlenecks restricting the industrialization of membrane absorption processes.

Utility model content

The utility model overcomes the deficiencies of the prior art, provides a coupling process and device using membrane aeration and membrane absorption, and well solves the problems existing in the prior art.

The technical scheme of the utility model is:

(1) Pretreatment process: Deoiling high ammonia nitrogen wastewater (mainly through air flotation and other processes), so that the oil content of the water entering the membrane aeration system in the next stage is lower than 5ppm, and then passed through a disc filter, security filter or The ultrafiltration membrane removes impurities from the ammonia nitrogen stock solution, so that the SS entering the membrane aeration system is lower than 10mg/L. It is also necessary to ensure that the surface tension entering the membrane aeration system should be greater than 60Mn/m, and adjust the pH value of the high ammonia nitrogen wastewater to 10-12;

(2) Membrane aeration: Pass the high ammonia nitrogen wastewater treated in step (1) into a closed membrane aeration tank. The membrane aeration device adopts a hydrophobic hollow fiber membrane system, and the membrane aeration device is placed in a closed aeration tank. pool;

(3) Membrane absorption: pump the high-ammonia nitrogen wastewater treated in step (2) into the inner side of the membrane filament of the hydrophobic membrane of the membrane absorption unit, and pump the acid absorption liquid (sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, organic acids, etc.) into the shell side of the hydrophobic membrane module for absorption, and the absorption liquid is operated in a circular manner; further preferably, the membrane absorption unit adopts the form of multi-stage series connection or/and parallel connection, and the high ammonia nitrogen wastewater side adopts multi-stage series connection or/and parallel connection for continuous treatment, According to the requirements of the treated water volume and the processing capacity of the single membrane of the membrane absorption unit, the appropriate number of parallel series is arranged, and the series stage is determined according to the ammonia nitrogen content of the high ammonia nitrogen raw water and the actual requirements of the discharged ammonia nitrogen and the processing capacity of the single membrane of the membrane absorption unit. number; in order to ensure the processing capacity of industrial continuous operation, two absorption liquid tanks are used for the absorption liquid, and the operation is switched. The concentrated acid storage tank (8) continuously adds acid to the absorption liquid to maintain the acid content in the absorption liquid and offset the consumption of ammonia nitrogen in the absorption of high ammonia nitrogen wastewater; the absorption liquid storage tank a (6) and the absorption liquid storage tank b ( 7) On-line acidity meter (9), on-line ammonia nitrogen meter (10), and stirring paddle are installed inside; on-line acidity meter (9) and concentrated acid storage tank (8) jointly control the addition amount of concentrated acid to maintain the absorption liquid acid concentration; the online ammonia nitrogen meter (10) is used to monitor the concentration of by-products in the absorption liquid in real time; the continuous stirring of the stirring paddle is used to keep the medium in the absorption liquid continuously adding acid uniform.

(4) Cleaning and air washing: When the operating performance of the membrane weakens to less than 70% of the original processing capacity, or when it needs to be shut down for a long time due to other reasons, it is necessary to start the cleaning and air washing system. Membrane cleaning is to use appropriate chemical cleaning agents depending on the pollution situation. After chemical cleaning, it is necessary to use clean water to wash away the chemical agents remaining in the membrane system, and finally turn on the air pump to air wash and dry the system.

(5) Recovery of by-products: pump the absorbed liquid treated in step (3) into the by-product recovery system, and carry out processes such as concentration and crystallization of by-products for recovery and resource reuse.

The above-mentioned zero-discharge device for realizing high ammonia nitrogen waste water recycling is characterized in that the pretreatment system is connected to the waste water storage tank (1), the membrane aeration device (2) is placed in the waste water storage tank (1), and the membrane aeration device (2) A hydrophobic hollow fiber membrane system is adopted, the membrane aeration device (2) is connected with the fan (3), the upper end of the waste water storage tank (1) is respectively connected with the absorption liquid storage tank a and the lower end of the waste water storage tank (1) The outlet water is connected to the tube side inlet of the membrane absorption unit (4), and the fan (3) is also connected to the tube side inlet of the membrane absorption unit (4); the product water absorbed by the membrane absorption unit (4) is discharged from the membrane absorption unit ( 4); the shell side of the membrane absorption unit (4) forms two circulation loops with the absorption liquid storage tank a (6) and the absorption liquid storage tank b (7); the absorption liquid storage tank a (6) and the absorption liquid storage tank The lower end of b(7) is connected with the by-product recovery system. The absorption liquid storage tank a (6) and the absorption liquid storage tank b (7) are respectively connected with the concentrated acid liquid storage tank (8).

Both the absorption liquid storage tank a (6) and the absorption liquid storage tank b (7) are equipped with online acidity meter (9), online ammonia nitrogen meter (10), stirring paddle; online acidity meter (9) and concentrated acid liquid storage tank (8) chain control the amount of addition of concentrated acid to maintain the acid concentration of the absorption liquid; the online ammonia nitrogen meter (10) is used to monitor the concentration of by-products in the absorption liquid in real time; The medium is uniform; the concentrated acid storage tank continues to add acid to the absorption liquid to maintain the acid content in the absorption liquid and offset the consumption of ammonia nitrogen in the absorption of high ammonia nitrogen wastewater;

The structure of the hydrophobic hollow fiber membrane system used above is as follows: it mainly includes a membrane frame, beams, terminal pipes, curtain membrane modules, air distribution pipes, and air intake pipes; the membrane frame includes at least four parallel vertical beams, and the two ends of the terminal pipes They are respectively fixed on the upper part of two adjacent vertical beams A and vertical beam B, and multiple cross beams are fixed between vertical beam A and vertical beam B, and between the other two adjacent vertical beams C and vertical beam D are also fixed. Fix multiple beams, the position of the beam between the vertical beam A and the vertical beam B is staggered with the position of the beam between the vertical beam C and the vertical beam D; between the lower part of the vertical beam A and the vertical beam B or the vertical beam C and the vertical beam D The air distribution pipe is fixed between the lower parts, and the air distribution pipe communicates with the intake pipe; the curtain membrane module is a curtain structure composed of multiple hydrophobic hollow fiber membranes spaced in parallel, and the surface of the hydrophobic hollow fiber membranes is provided with a microporous structure ;One end of the curtain membrane module is fixed on the terminal pipe, and the other end is fixed on the air distribution pipe, and the hydrophobic hollow fiber membrane is connected with the air distribution pipe; It detours with the beams between the vertical beams C and D to form a space-folded curved structure. The membrane frame is a cuboid frame structure, the distance between vertical beam A and vertical beam B is long, the length of vertical beam A is high, and the direction perpendicular to the length and height is the width direction; the ratio of length: width: height is 1: (0.6～1): (1.2～1.8), the bottom ends of the 4 sides of the cuboid all have fixed tripods. The distance between two adjacent hydrophobic hollow fiber membranes is 4-5mm. The terminal pipe is fixed parallel to the uppermost beam; the air distribution pipe is fixed parallel to the lowermost beam.

Finally, a zero-discharge process for resource utilization of high ammonia nitrogen wastewater is realized by adopting the coupling process of membrane aeration and membrane absorption.

In order to effectively utilize the permeation distillation, the absorption liquid only needs to be equipped with acidic absorption liquid to meet the pipeline operation at the initial stage, accounting for about 20-30% of the volume of the absorption liquid tank. The initial configuration is an acidic absorption solution with a mass percentage concentration of 5%-20%.

The membrane materials used in the membrane aeration device (2) and the membrane absorption unit are hydrophobic membrane materials such as PTFE, PP, PVDF, etc., and the module form is a hollow fiber membrane module, and the pore diameter of the module is required to be 0.1-0.01 μm.

In the cleaning and air washing system, the cleaning process mainly uses water or chemical agents to clean the membrane. The type and concentration of the specific agents used depend on the pollution situation, such as using chemical agents to clean the membrane.

In the recovery of by-products, the cleaning process is mainly to use water or chemical agents to clean the membrane. The type and concentration of the specific agents used depend on the pollution situation, such as using chemical agents to clean the membrane.

The beneficial effects of the utility model are as follows: firstly, about 60% of the ammonia nitrogen in the ammonia nitrogen wastewater is removed by membrane aeration, and then about 99% of the ammonia nitrogen in the wastewater is removed by membrane absorption multi-stage deamination, and the total removal efficiency exceeds 99%. %, so that the high ammonia nitrogen raw water can achieve the effect of direct discharge after treatment. The ammonia gas separated in the membrane aeration system is directly passed into the absorption liquid tank during the membrane absorption process to react the excess acid in the absorption liquid tank. Then pass the treated absorption liquid into the by-product recovery system to treat the high-concentration absorption liquid. When the operating capacity is reduced to 70% of the original processing capacity, or when it needs to be shut down for a long time, the cleaning-air washing system needs to be turned on to maintain and clean the system to maintain the long-term stable operation of the system. The utility model solves the hydrophilization of membrane filaments, makes good use of the volume expansion of the absorption liquid brought about by the osmotic distillation, realizes effective water saving, and makes the concentration of the absorption liquid product close to saturation, reduces the operating cost and improves the production efficiency of the absorption liquid. Treatment efficiency, realizing the possibility of industrialized large-scale true zero-emission operation of continuous membrane absorption.

The utility model can obtain more than 99% ammonia nitrogen removal efficiency, realize the standard of direct discharge of high-concentration ammonia nitrogen wastewater, and can recycle more than 99% of ammonia nitrogen contained in the wastewater into effective chemical products or fertilizers. It effectively prolongs the applicable life of the membrane, and has many advantages such as low construction investment cost, low operating cost, small footprint, and high treatment efficiency.

Description of drawings

Figure 1 is a diagram of the membrane aeration and membrane absorption coupling process device;

Fig. 2 is a structural schematic diagram of a membrane aeration device;

1. Wastewater storage tank; 2. Membrane aeration device; 3. Fan; 4. Membrane absorption unit assembly; 5. Produced water; 6. Absorption liquid storage tank a; 7. Absorption liquid storage tank b; 8. Concentrated acid storage Tank; 9. On-line acidity meter; 10. On-line ammonia nitrogen meter; 11 Terminal pipe; 12 Beam; 13 Hydrophobic hollow fiber membrane; 14 Air distribution pipe; 15 Bottom beam; trachea; 19 vertical beam A of the membrane frame; 20 vertical beam B of the membrane frame; 21 vertical beam C of the membrane frame; 22 vertical beam D of the membrane frame.

detailed description

The utility model will be further described below in conjunction with the examples, but the utility model is not limited to the following examples.

Figure 1 is the diagram of the membrane aeration and membrane absorption coupling process device.

a. The ammonia-containing wastewater enters the wastewater storage tank (1) after pretreatment, and the ammonia-containing wastewater is pumped from the wastewater storage tank into the inner side of the membrane module (4) (i.e., the tube side), and the ammonia in the wastewater diffuses to the membrane through the membrane pores On the other side, the product water (5) is discharged;

B, membrane aeration device (2) is placed in waste water tank (1), the upper end of waste water tank (1) is communicated with absorption liquid storage tank; Partial ammonia nitrogen is contained in the form of _NH3 by-product to be transferred to by-product with excessive acid Absorption of acidic hand sanitizer in the absorption liquid storage tank of the recovery system;

c. The newly configured acidic absorption liquid is pumped from the absorption liquid storage tank (6) into the outer side of the membrane module (that is, the shell side) of the membrane absorption unit (4), and flows in the same direction as the wastewater along the outer wall of the membrane fiber on the shell side. After absorbing the ammonia diffused from the other side of the membrane, it flows back to the absorption liquid storage tank; the membrane absorption unit is assembled in multi-stage parallel or/and series;

d. The device has two parallel absorption liquid storage tanks, the absorption liquid storage tank a (6) and the absorption liquid storage tank b (7) are equipped with online acidity meter (9), online ammonia nitrogen meter (10), stirring paddle ; On-line acidity meter (9) and concentrated acid storage tank (8) are interlocked to control the addition of concentrated acid to maintain the acid concentration of the absorption liquid; on-line ammonia nitrogen meter (10) is used to monitor the concentration of by-products in the absorption liquid in real time; The continuous stirring is used to keep the medium in the absorption liquid that is continuously added with acid uniform; the concentrated acid storage tank continues to add acid to the absorption liquid to maintain the acid content in the absorption liquid and offset the consumption of ammonia nitrogen in the absorption of high ammonia nitrogen wastewater; When the by-products in the absorption liquid in one of the absorption liquid storage tanks a(6) reach a certain concentration, switch to the other absorption liquid storage tank b(7), and the absorption liquid in the absorption liquid storage tank b(7) is pumped into the membrane In the component (2), that is, the ammonia gas blown out by the aeration device (2) is passed into the absorption liquid storage tank a (6) to neutralize the excess acid in the absorption liquid storage tank a (6) and make the The concentration of by-products in the absorption liquid increases again. When the acid in the absorption liquid storage tank a (6) is no longer excessive, blow off the ammonia gas from the aeration device (2) and pass it into the absorption liquid storage tank b (7). The absorption liquid in the absorption liquid storage tank a (6) is pumped into the by-product recovery system, and after the absorption liquid storage tank a (6) is emptied, the absorption liquid is re-prepared according to a certain ratio; when the absorption liquid storage tank b (7 ) when the by-product reaches a certain concentration again, switch to the absorption liquid in the absorption liquid storage tank a (6) and pump into the membrane module (4), realizing the continuity of operation;

e. The process device has air washing and backwashing process: air washing and aeration device share a fan (3);

f. The process adopts the coupling process of membrane aeration and membrane absorption to realize the zero discharge process of high ammonia nitrogen wastewater resource utilization.

Example 1

The combined process of membrane aeration and membrane absorption is used to treat coal chemical wastewater with an ammonia nitrogen concentration of 5000mg/L per tonne.

(1) Pretreatment process: Deoiling the high ammonia nitrogen stock solution mainly through coalescing materials, so that the oil content in the water is lower than 5ppm, and removing impurities from the ammonia nitrogen stock solution through a disc filter, so that the SS entering the membrane aeration system is lower than 10mg/L. The ammonia nitrogen concentration of the water after pretreatment is 5000mg/L.

(2) Membrane aeration system: The pretreated high-ammonia-nitrogen wastewater is passed into a well-sealed membrane aeration tank, and the membrane aeration system uses a hydrophobic hollow fiber membrane. The concentration of ammonia nitrogen through the membrane aeration system will be 2000mg/L.

(3) Membrane absorption system: pump the high-ammonia nitrogen wastewater treated by the membrane aeration system into the inner side of the membrane filament of the hydrophobic membrane of the membrane absorption unit, and use 10% sulfuric acid as the absorption liquid to pump it into the shell side of the hydrophobic membrane module to absorb The liquid is operated in a circulation mode, and the raw water side with high ammonia nitrogen is continuously treated with three-stage series and three-stage parallel series of hydrophobic membrane modules. The concentration of ammonia nitrogen after treatment is 40mg/L, and the removal rate of diazepam in the membrane absorption system is 98%. The total removal rate is 99.2%. In order to ensure the processing capacity of industrial continuous operation, two absorption liquid tanks are used for the absorption liquid, and the operation is switched.

The device has two absorption liquid storage tanks, when the concentration of ammonium sulfate in the absorption liquid in one of the absorption liquid storage tank a (6) reaches 30%, switch to the ammonium sulfate in the other absorption liquid storage tank b (6) The absorption liquid is pumped into the membrane module (6), and at this time, the ammonia gas blown out by the aeration device (2) is passed into the absorption liquid storage tank a (6) to neutralize 10% of excess ammonia gas in the absorption liquid tank acid, and make the concentration of ammonium sulfate in the absorption liquid reach 40%, when the acid in the absorption liquid storage tank is no longer excessive, blow off the ammonia gas from the aeration device (2) and pass it into the absorption liquid storage tank b (6) , pump the absorption liquid in the absorption liquid storage tank a (6) into the by-product recovery system, after the absorption liquid storage tank a (6) is emptied, and then prepare 300L of 10% sulfuric acid absorption liquid according to a certain ratio for standby, Until the by-product concentration in the absorption liquid storage tank b (6) reaches 30% again, switch to pump the absorption liquid in the absorption liquid storage tank a (6) into the membrane module.

(4) Cleaning and air washing system: When the operating performance of the membrane weakens to below 70% of the original treatment capacity, the water quality cleaning cycle is about 6 months, and the cleaning and air washing system is started. Membrane cleaning is to use appropriate chemical cleaning agents depending on the pollution situation. After chemical cleaning, it is necessary to use clean water to wash away the chemical agents remaining in the membrane system, and finally turn on the air pump to air wash and dry the system.

(5) By-product recovery system: pump the absorbed liquid treated in step (3) into the by-product recovery system, and carry out processes such as concentration and crystallization of by-products for recovery and resource reuse.

Finally, a zero-discharge process for resource utilization of high ammonia nitrogen wastewater is realized by adopting the coupling process of membrane aeration and membrane absorption.

Claims (5)

1. A device for zero discharge treatment of high ammonia nitrogen waste water resource utilization, characterized in that the pretreatment system is connected to the waste water storage tank, the membrane aeration device is placed in the waste water storage tank, and the membrane aeration device adopts hydrophobic hollow fibers Membrane system, the membrane aeration device is connected to the fan, the upper end of the wastewater storage tank is connected to the absorption liquid storage tank a and respectively, the water outlet from the lower end of the wastewater storage tank is connected to the tube side inlet of the membrane absorption unit, and the fan is also connected to the tube side of the membrane absorption unit The water produced after being absorbed by the membrane absorption unit is discharged from the membrane absorption unit; the shell side of the membrane absorption unit forms two circulation loops with the absorption liquid storage tank a and the absorption liquid storage tank b respectively; the absorption liquid storage tank a and the absorption liquid The lower end of the liquid storage tank b is connected to the by-product recovery system; the absorption liquid storage tank a and the absorption liquid storage tank b are respectively connected to the concentrated acid liquid storage tank; The structure of the hydrophobic hollow fiber membrane system used above is as follows: it mainly includes a membrane frame, beams, terminal pipes, curtain membrane modules, air distribution pipes, and air intake pipes; the membrane frame includes at least four parallel vertical beams, and the two ends of the terminal pipes They are respectively fixed on the upper part of two adjacent vertical beams A and vertical beam B, and multiple cross beams are fixed between vertical beam A and vertical beam B, and between the other two adjacent vertical beams C and vertical beam D are also fixed. Fix multiple beams, the position of the beam between the vertical beam A and the vertical beam B is staggered with the position of the beam between the vertical beam C and the vertical beam D; between the lower part of the vertical beam A and the vertical beam B or the vertical beam C and the vertical beam D The air distribution pipe is fixed between the lower parts, and the air distribution pipe communicates with the intake pipe; the curtain membrane module is a curtain structure composed of multiple hydrophobic hollow fiber membranes spaced in parallel, and the surface of the hydrophobic hollow fiber membranes is provided with a microporous structure ;One end of the curtain membrane module is fixed on the terminal pipe, and the other end is fixed on the air distribution pipe, and the hydrophobic hollow fiber membrane is connected with the air distribution pipe; It detours with the beams between the vertical beams C and D to form a space-folded curved structure. 2. The device according to claim 1, characterized in that the membrane absorption unit adopts the form of multi-stage series connection or/and parallel connection. 3. according to the described device of claim 1, it is characterized in that, membrane frame is cuboid frame structure, and the distance between vertical beam A and vertical beam B is long, and the length of vertical beam A is high, perpendicular to length and height The direction is the width direction; the ratio of length: width: height is 1: (0.6-1): (1.2-1.8), and the bottom ends of the four sides of the cuboid are all provided with tripods for fixing. 4. according to the described device of claim 1, it is characterized in that, the distance between two adjacent hydrophobic hollow fiber membranes is 4-5mm, and the terminal pipe is fixed together with the top beam in parallel; the air distribution pipe is connected with the bottom beam fixed together in parallel. 5. according to the described device of claim 1, it is characterized in that, in the absorption liquid storage tank a and the absorption liquid storage tank b, online acidity meter, online ammonia nitrogen instrument, stirring paddle are all installed; Online acidity meter and concentrated acid liquid storage tank The addition of concentrated acid is controlled in chain to maintain the acid concentration of the absorption liquid; the online ammonia nitrogen meter is used to monitor the concentration of by-products in the absorption liquid in real time; the continuous stirring of the stirring paddle is used to keep the medium in the absorption liquid with continuous acid addition uniform.