Full-membrane treatment process and device for purifying and concentrating acid in acidic wastewater

Abstract

The invention relates to the technical field of acid wastewater treatment and purification, and particularly discloses a whole membrane treatment process and device for purifying and concentrating acid in acid wastewater. The device comprises a main frame, a raw water tank is arranged on one side of the upper portion of the main frame, and a first security filter is arranged on one side of the raw water tank; an ultrafiltration assembly is arranged on the side, away from the raw water tank, of the first security filter, a heat exchange assembly is arranged below the side, away from the first security filter, of the ultrafiltration assembly, a purification assembly is arranged on the side, close to the ultrafiltration assembly, of the heat exchange assembly, and a nanofiltration reverse osmosis assembly is arranged on the side, away from the heat exchange assembly, of the purification assembly; an acceleration assembly is arranged on one side, far away from the purification assembly, of the nanofiltration reverse osmosis assembly. Through a multi-step membrane treatment process, impurities such as suspended solids, colloids, organic matters, various ions and microorganisms in the acid wastewater can be effectively removed.

Description

Technical Field

[0001] The invention relates to the technical field of acid wastewater treatment and purification, and in particular to a full-membrane treatment process and device for purifying and concentrating acid in acid wastewater. Background Art

[0002] At present, with the rapid development of my country's economy, the industrial and technological levels have made great progress, and the chemical and pharmaceutical industries have developed very rapidly. However, these industries will produce a large number of toxic and harmful substances in the process of product research and development and production, and the wastewater produced contains a large amount of acidic substances and then produces polluted acid water. These acid waters contain a large amount of recyclable acidic substances. These substances will not only cause waste of original production resources, but also are difficult to handle. At the same time, simple treatment and discharge will cause a lot of pollution. Therefore, the treatment process of acidic wastewater has great practical significance.

[0003] At present, there are several treatment processes for acidic wastewater:

[0004] Neutralization valve: The most commonly used disposal process is the neutralization method. About 53% of waste acid disposal companies use acid-base neutralization technology, of which about 38% of companies use neutralization precipitation and triple-effect evaporation to treat acidic wastewater. Although the effluent quality is good, the waste salt residue produced by evaporation is difficult to dispose of, and heavy metals cannot be recycled, which increases the treatment cost; about 50% of companies use neutralization precipitation to prepare tin hydroxide products, but lack the corresponding heavy metal removal process, and there is a problem of heavy metal transfer.

[0005] Roasting method: The treatment equipment of the roasting method is mainly roasting furnace, and the acid recovery rate and purity of this method are relatively high. Because it needs to operate under high temperature conditions, the equipment investment and operation cost are much higher than other disposal methods, and the furnace bottom is prone to blockage, and the operation management requirements are very strict. Usually large steel processing enterprises use high-temperature regeneration technology to treat acidic wastewater, recover acid and recycle it.

[0006] Membrane separation method: The membrane separation method has a high recovery rate, thorough separation, simple operation, high degree of automation, and a good working environment. It can bring both economic benefits and good environmental benefits. It is an effective method for treating acidic wastewater. Compared with the neutralization method, the membrane treatment method not only recovers acid but also saves the use of alkali, greatly reduces the amount of sludge generated, and has broad application prospects.

[0007] Ion exchange method: Ion exchange method is a simple waste acid treatment technology, which has certain advantages in waste acid regeneration. It has a large treatment capacity and the resin can be regenerated. Fully utilizing the recycling function of ion exchange technology can also bring certain economic benefits. However, the one-time investment cost of ion exchange technology is high, and the operation and management requirements are strict. The resin needs to be replaced regularly and there are regeneration problems.

[0008] Comprehensive comparison shows that membrane separation is the most cost-effective method for acid treatment at present.

[0009] Patent document with publication number "CN115501763BA" discloses a preparation and application method of a highly permeable selective ion separation membrane, wherein the ion separation membrane is based on an ultra-microfiltration membrane with a pore size of 5 to 1000 nm as a base membrane; on the surface of the base membrane there is a covalent organic framework (COF) separation layer formed by condensation of aldehyde monomers and amine monomers containing guanidine groups, and the pore size is 0.5 to 5 nm; the above invention realizes simultaneous separation of anions and cations based on a mixing mechanism, has high permeability selectivity when used for the treatment of acidic wastewater, realizes simultaneous separation of anions and cations, and thus achieves the purpose of treating acidic wastewater and selectively recovering acid; the membrane preparation method of the above invention is simple and stable, the prepared membrane is stable in acidic wastewater, and can treat and recover acidic wastewater with low energy consumption and environmental protection.

[0010] However, due to the limitations of materials and membrane preparation processes, the existing technology is prone to secondary pollution when treating acidic wastewater, which may damage the environment and lead to a waste of acid resources. Summary of the invention

[0011] In order to solve the problem that membrane components are easily contaminated in the prior art, the present invention provides a full-membrane treatment process and device for purifying and concentrating acid in acidic wastewater, and recycles acid resources in acidic wastewater through multi-stage treatment to effectively avoid secondary pollution.

[0012] The first technical solution of the present invention is a full-membrane treatment device for purifying and concentrating acid in acidic wastewater, comprising a main frame, a raw water tank is arranged on one side above the main frame, a first security filter is arranged on one side of the raw water tank, an ultrafiltration component is arranged on the side of the first security filter away from the raw water tank, a heat exchange component is arranged below the side of the ultrafiltration component away from the first security filter, a purification component is arranged on the side of the heat exchange component close to the ultrafiltration component, a nanofiltration reverse osmosis component is arranged on the side of the purification component away from the heat exchange component, an acceleration component is arranged on the side of the nanofiltration reverse osmosis component away from the purification component, and a separation component is arranged on the side of the acceleration component away from the nanofiltration reverse osmosis component.

[0013] The present invention constructs a complete and systematic full-membrane treatment device architecture for acid purification and concentration of acidic wastewater. By rationally arranging components such as the raw water tank, various filters, membrane components, heat exchange, purification, nanofiltration, acceleration and separation components, it lays the foundation for realizing an efficient acidic wastewater treatment process, so that the entire treatment process is connected in an orderly manner and each link is closely coordinated, thereby ensuring the feasibility and stability of the process from the hardware level.

[0014] Preferably, a water inlet pipe is provided on one side of the raw water tank, a first flow guide pipe is provided on the side of the raw water tank away from the water inlet pipe, a water inlet pump is provided on the end of the first flow guide pipe away from the raw water tank, a second flow guide pipe is provided on the side of the water inlet pump away from the first flow guide pipe, and the end of the second flow guide pipe away from the water inlet pump is connected to the first safety filter.

[0015] The initial path of acidic wastewater entering the treatment process from the raw water tank is clarified, and the connection design between the water inlet pipe and the subsequent diversion pipe and water inlet pump ensures that the wastewater can be transported to the first safety filter stably and efficiently to avoid the risk of leakage and blockage. At the same time, it provides a continuous and uniform water flow supply for subsequent fine treatment to ensure the continuity of the treatment rhythm.

[0016] Preferably, the raw water tank includes a spiral tube, which is arranged at the top of the raw water tank, a magnetic column is arranged on the inner side of the spiral tube, a sedimentation barrel is arranged at the bottom end of the spiral tube, a filter plate is arranged at the bottom end of the sedimentation barrel, and a pH and flow detection ring is arranged on the outer side of the filter plate.

[0017] The spiral tube, magnetic column, sedimentation barrel, filter plate and other components in the raw water tank work together to remove magnetic impurities, large suspended particles and fine impurities to the maximum extent before the wastewater enters the core treatment link. The pH and flow detection ring monitors the water quality in real time, providing accurate data support for subsequent targeted treatment, effectively reducing the burden on subsequent treatment units, improving overall treatment efficiency, and extending the service life of subsequent precision components.

[0018] Preferably, a third flow guide pipe is provided at the bottom end of the first security filter, a cache water tank is provided at the bottom end of the third flow guide pipe, a fourth flow guide pipe is provided on one side of the cache water tank, a circulation pump is provided at the end of the fourth flow guide pipe away from the cache water tank, a fifth flow guide pipe is provided at the end of the circulation pump away from the fourth flow guide pipe, a three-way valve is provided at the end of the fifth flow guide pipe away from the circulation pump, and the three-way valve is provided above the ultrafiltration component.

[0019] The guide pipe design at the bottom of the first safety filter diverts the concentrate to the buffer water tank. The buffer water tank is connected to the circulation pump. On the one hand, it realizes the temporary storage and centralized management of the concentrate to avoid disorderly discharge of concentrate that affects the environment or interferes with other processes. On the other hand, the circulation pump can flexibly allocate the liquid in the buffer water tank to optimize resource utilization and improve treatment effects.

[0020] Preferably, the ultrafiltration component includes a membrane shell, which is arranged on one side of the first security filter, a fixing frame is arranged on the inner side of the membrane shell, a plurality of ultrafiltration pipes are arranged on the inner side of the fixing frame, a transmission column is fixedly arranged at the center of the fixing frame, a driving motor is arranged at the bottom end of the driving column, and the output end of the driving motor is fixedly connected to the transmission column.

[0021] The membrane shell, fixing frame, ultrafiltration pipe, transmission column and driving motor combination in the ultrafiltration component drives the transmission column to rotate through the driving motor, optimizes the water flow state in the ultrafiltration pipe, promotes more efficient separation of impurities and water molecules in the wastewater, and improves the ultrafiltration efficiency.

[0022] Preferably, a sixth flow guide tube is provided on one side of the membrane shell, a pressure gauge is provided on the side of the sixth flow guide tube, a temperature sensor is provided on the side of the pressure gauge away from the membrane shell, the bottom end of the temperature sensor is connected to the sixth flow guide tube, a flow meter is provided on the side of the temperature sensor away from the pressure gauge, the bottom end of the flow meter is connected to the sixth flow guide tube, a control valve is provided on one end of the sixth flow guide tube away from the membrane shell, a seventh flow guide tube is provided on one end of the control valve away from the sixth flow guide tube, and a first water production tank is provided on one end of the seventh flow guide tube away from the control valve. An eighth flow guide pipe is provided on one side of the first water production tank, a booster pump is provided on the side of the eighth flow guide pipe away from the first water production tank, a ninth flow guide pipe is provided on one end of the booster pump away from the eighth flow guide pipe, a second safety filter is provided on one end of the ninth flow guide pipe away from the booster pump, a tenth flow guide pipe is provided on one end of the second safety filter away from the ninth flow guide pipe, a high-pressure pump is provided on one end of the tenth flow guide pipe away from the second safety filter, an eleventh flow guide pipe is provided on one end of the high-pressure pump away from the tenth flow guide pipe, and the eleventh flow guide pipe is connected to the heat exchange component.

[0023] The monitoring and control components on one side of the membrane shell, including the pressure gauge, temperature sensor, flow meter and control valve, monitor the key parameters of the ultrafiltration process in real time to ensure that the ultrafiltration is carried out under stable pressure, suitable temperature and reasonable flow rate, avoiding membrane damage or poor ultrafiltration effect due to parameter fluctuations.

[0024] Preferably, the heat exchange assembly includes an insulating shell, which is fixedly connected to the main frame, a first heat exchange row is arranged on one side of the insulating shell, a second heat exchange row is arranged on the side of the insulating shell away from the first heat exchange row, a twelfth guide pipe is arranged on the side of the second heat exchange row away from the insulating shell, a ball valve is arranged on the side of the twelfth guide pipe away from the second heat exchange row, a thirteenth guide pipe is arranged on the end of the ball valve away from the twelfth guide pipe, and the thirteenth guide pipe is connected to the purification assembly.

[0025] The heat exchange component is designed with an insulating shell, heat exchange rows, internal liquid exchange tubes, gas exchange tubes, etc., and uses the principles of heat conduction and heat convection to quickly and accurately heat the ultrafiltration water product, meet the specific requirements of subsequent purification, nanofiltration and other links for water temperature, ensure the chemical reaction rate and membrane separation effect, and improve the stability and reliability of the overall process.

[0026] Preferably, a heat funnel is provided inside the heat-insulating shell, a plurality of liquid exchange tubes are provided in the middle of the heat funnel, one end of the liquid exchange tube is connected to the first heat exchange row, and one end of the liquid exchange tube away from the first heat exchange row is connected to the second heat exchange row;

[0027] A first gas exchange tube is arranged on one side of the top of the heat funnel, a heating ring is arranged on the side of the first gas exchange tube, the bottom end of the first gas exchange tube is connected to the bottom end of the heat funnel, and a second gas exchange tube is arranged on the side of the heat funnel away from the first gas exchange tube.

[0028] In the present invention, the heat funnel and the connected liquid exchange tube enhance the heat exchange area and efficiency, the gas exchange tube and the heating ring assist in adjusting the temperature, ensure uniform and efficient heat exchange, optimize the subsequent power-on purification effect, reduce energy waste, and improve heat exchange efficiency.

[0029] Preferably, the purification component includes an insulating shell, which is fixedly connected to the main frame, an electrode plate is arranged on the side of the insulating shell, a liquid level rod is slidably connected to the top of the insulating shell, a liquid level display is arranged on the top of the liquid level rod, and an insulating tube is arranged on one side of the insulating shell.

[0030] The design of the purification component's insulating shell, electrode plate, liquid level ball bar and display provides a safe and stable environment for the power-on purification process, accurately controls voltage, time and temperature, and uses the principle of electrodialysis to efficiently remove high-hardness cations to obtain high-purity acid purification liquid; liquid level monitoring ensures real-time operational safety, avoids accidents such as short circuits caused by abnormal liquid levels, and ensures stable operation of the purification process.

[0031] Preferably, the nanofiltration reverse osmosis component includes a first filter bottle, which is arranged on one side of an insulating tube, a first branch pipe is arranged on the side of the insulating tube close to the first filter bottle, and the end of the first branch pipe away from the insulating tube is connected to the first filter bottle, a fourteenth guide pipe is arranged at the top of the first filter bottle, and a second filter bottle is arranged at the end of the fourteenth guide pipe away from the first filter bottle, a second branch pipe is arranged on the side of the insulating tube close to the second filter bottle, and the end of the second branch pipe away from the insulating tube is connected to the second filter bottle, a fifteenth guide pipe is arranged at the top of the second filter bottle, and a third filter bottle is arranged at the end of the fifteenth guide pipe away from the second filter bottle, the end of the insulating tube away from the insulating shell is connected to the third filter bottle, and a sixteenth guide pipe is arranged at the top of the third filter bottle, and the sixteenth guide pipe is connected to the acceleration component.

[0032] The nanofiltration reverse osmosis components are connected through multiple filter bottles and branch pipes to construct a graded nanofiltration system. According to the characteristics of different molecular weight cutoffs, the acid purification liquid is gradually concentrated, the organic matter is accurately separated, and the acid concentration is increased. Compared with a single nanofiltration link, it can recover acid resources more finely, improve product purity, reduce the difficulty of subsequent processing, and maximize resource utilization.

[0033] Preferably, a nanofiltration membrane is arranged on the top of the first filter bottle, a plurality of liquid conduits are arranged below the nanofiltration membrane, a first reverse osmosis barrel is arranged at the bottom end of the liquid conduits, a plurality of reverse osmosis membrane tubes are arranged on the inner side of the first reverse osmosis barrel, and a second reverse osmosis barrel is arranged below the first reverse osmosis barrel.

[0034] The nanofiltration membrane, liquid conduit, concentration barrel, reverse osmosis membrane tube and other components in the first filter bottle can efficiently intercept large molecular organic matter at the initial stage of nanofiltration, initially increase the acid concentration, provide more suitable feed for subsequent secondary nanofiltration, optimize the overall nanofiltration process, reduce the pollution and loss of subsequent nanofiltration membranes, and extend the service life of nanofiltration reverse osmosis components.

[0035] Preferably, the acceleration assembly comprises an acceleration bracket, which is arranged on a main frame, a first-level acceleration tube is arranged on the inner side of the acceleration bracket, a second-level acceleration tube is arranged at one end of the first-level acceleration tube, a third-level acceleration tube is arranged at one end of the second-level acceleration tube away from the first-level acceleration tube, a seventeenth guide tube is arranged at one end of the third-level acceleration tube away from the second-level acceleration tube, and the seventeenth guide tube is connected to the separation assembly.

[0036] The multi-stage accelerating tube design of the accelerating assembly utilizes the principles of fluid mechanics to enable the concentrated water to achieve high speed in a short period of time. With the synergistic effect of high-speed impact and membrane separation, the separation effect is enhanced. Compared with membrane separation at conventional flow rates, it can more thoroughly separate impurities and target products, improve the three-stage concentration and separation efficiency, and reduce processing time and energy consumption.

[0037] Preferably, the separation assembly includes a fourth filter bottle, which is fixedly connected to the main frame, a first separation tube is provided on the top side of the fourth filter bottle, and an end of the first separation tube away from the fourth filter bottle is connected to a final concentrated water tank, and a second separation tube is provided on the bottom side of the fourth filter bottle, and an end of the second separation tube away from the fourth filter bottle is connected to a final produced water tank.

[0038] The fourth filter bottle of the separation component and the connected separation tube and water production tank are designed to accurately divert the produced water and acidic concentrated water according to the acidity test results, realize the reuse or discharge of pure water and the recycling of acidic concentrated water, avoid resource waste and environmental pollution, complete the final closed loop of the entire acid wastewater treatment process, and ensure the effectiveness and environmental friendliness of the treatment results.

[0039] The second technical solution of the present invention is a full membrane treatment process for purifying and concentrating the acid in the acidic wastewater, comprising the following steps:

[0040] (S01) introducing acidic wastewater into a raw water tank, and then pumping the acidic wastewater into a first security filter, and after filtration, pumping the filtered water into an ultrafiltration component for ultrafiltration treatment, and obtaining ultrafiltration product water and concentrated water after ultrafiltration, discharging the ultrafiltration concentrated water, and introducing the ultrafiltration product water back into the raw water tank for cyclic ultrafiltration;

[0041] (S02) introducing the ultrafiltration product water after the cyclic ultrafiltration into the heat exchange component, adjusting the temperature of the ultrafiltration concentrated water, and then introducing the ultrafiltration product water after the temperature adjustment into the purification component for purification treatment, obtaining purified product water and concentrated water after purification, and discharging the purified concentrated water;

[0042] (S03) introducing the purified produced water into the first filter bottle, performing nanofiltration and one-stage reverse osmosis treatment to obtain one-stage concentrated produced water and concentrated water, and discharging the one-stage concentrated produced water into the final produced water tank;

[0043] (S04) introducing the concentrated water from the first stage into the second filter bottle, performing nanofiltration and the first stage and second stage reverse osmosis treatment to obtain the first stage and second stage concentrated water and concentrated water, and discharging the first stage and second stage concentrated water into the final water production tank;

[0044] (S05) introducing the concentrated water from the first stage and second stage into the third filter bottle, performing nanofiltration and first stage and third stage reverse osmosis treatment to obtain the first stage and third stage concentrated water and concentrated water, and discharging the first stage and third stage concentrated water into the final water production tank;

[0045] (S06) The first-stage three-stage concentrated concentrated water is introduced into the first-stage acceleration tube for acceleration treatment, and then the first-stage three-stage concentrated concentrated water after the acceleration treatment is introduced into the fourth filter bottle for secondary reverse osmosis treatment to obtain secondary concentrated water and concentrated water, and the secondary concentrated water is introduced into the final water production tank, and the secondary concentrated concentrated water is discharged into the final concentrated water tank to achieve the recycling of acidic wastewater.

[0046] The present invention can effectively remove impurities such as suspended matter, colloids, organic matter, various ions, and microorganisms in acidic wastewater through multi-step membrane treatment processes, such as ultrafiltration, nanofiltration, and reverse osmosis. For example, ultrafiltration can intercept macromolecular organic matter and microorganisms, nanofiltration has a good removal effect on divalent ions and some organic matter, and reverse osmosis can remove almost all ions and residual impurities, so that the final water quality reaches a high standard and meets the requirements of production reuse or safe discharge. In terms of conductivity indicators, from the initial high conductivity of acidic wastewater, after multi-step treatment, the final water conductivity can be lower than 1μS / cm, which effectively reduces the content of dissolved solids in water.

[0047] The whole process is centered on full membrane treatment, which removes impurities while concentrating the acid in the acidic wastewater. The membrane separation process at each stage is carried out in a targeted manner according to the different characteristics of the acid and impurities, so that the acid is enriched in the concentrated water, the acid concentration is increased, the acid is purified and concentrated, and conditions are created for the recycling of the acid.

[0048] The cyclic ultrafiltration process can be treated multiple times according to the water quality conditions to ensure the stability of the ultrafiltration water quality; the heat exchange component adjusts the temperature to create suitable conditions for subsequent purification and membrane treatment, thereby improving the treatment efficiency; the first-stage acceleration tube accelerates the concentrated water, enhancing the mass transfer efficiency during the subsequent second-stage reverse osmosis treatment and improving the treatment capacity of the overall system.

[0049] Preferably, in the step (S01), the acidic wastewater is first introduced into the raw water tank, and then the acidic wastewater in the raw water tank is pumped into the first security filter. After filtration, the filtered water is pumped into the ultrafiltration component for ultrafiltration treatment to obtain ultrafiltration product water and concentrated water, and the ultrafiltration product water is introduced back to the raw water tank for 2 to 5 cycles of ultrafiltration treatment.

[0050] The ultrafiltration component uses an ultrafiltration membrane made of polyvinylidene fluoride (PVDF), with a molecular weight cutoff of 1000 to 10000 Daltons and an operating pressure of 0.1 to 0.3 MPa. During the ultrafiltration process, under the action of pressure, small molecules and water in the acidic wastewater pass through the ultrafiltration membrane to form ultrafiltration water, while large molecular organic matter, colloids, microorganisms and some high-valent ions are retained to form concentrated water.

[0051] The first security filter uses a PP melt-blown filter element with a filtration accuracy of 5 to 10 microns. It can effectively intercept suspended matter, colloids, rust and other impurities with a diameter larger than the filter element pore size, ensuring that the water quality entering the subsequent process is relatively clean.

[0052] The present invention leads the ultrafiltration water back to the raw water tank for 2 to 5 cycles of ultrafiltration, and flexibly adjusts the number of cycles according to the water quality, so as to deeply treat the acidic wastewater. Multiple cycles can further reduce the impurity content in the ultrafiltration concentrated water, meet the water quality requirements of the subsequent treatment links, and improve the reliability of the entire treatment process.

[0053] Preferably, in the step (S02), the ultrafiltration product water after circulating ultrafiltration is first introduced into the heat exchange component, the temperature of the ultrafiltration concentrated water is increased to 25-40°C, and then the ultrafiltration product water after temperature adjustment is introduced into the purification component, and purified using an electric field of 500-1000V / m to obtain purified product water and concentrated water, and the purified concentrated water is discharged.

[0054] The present invention introduces the ultrafiltration water produced after the cyclic ultrafiltration into the heat exchange component and heats it to 25-40°C. At this temperature, the molecular thermal motion is accelerated, the activity of the ions is enhanced, and the ion exchange efficiency in the subsequent purification component can be significantly improved, thereby shortening the overall purification processing time and increasing the processing volume per unit time.

[0055] The present invention applies an electric field of 500 to 1000 V / m in the purification component. Under the action of the electric field, the migration speed of ions is accelerated, which can not only enhance the adsorption and exchange capacity of cations and anions in water, but also promote some tiny particles or organic matter combined with ions to be taken out of the system along with the ion migration, more effectively remove impurity ions in water, significantly reduce the conductivity of purified water, improve water purity, and make the quality of purified water more in line with the requirements of subsequent treatment or reuse.

[0056] Preferably, in the step (S03), the purified product water is first introduced into the first filter bottle, and nanofiltration and one-stage reverse osmosis treatment are performed to obtain one-stage concentrated product water and concentrated water, and the one-stage concentrated product water is discharged into the final product water tank; the molecular weight cutoff of the nanofiltration treatment is 200 to 1000Da, and the operating pressure is 0.5 to 1.5MPa; the operating pressure of the one-stage reverse osmosis treatment is 1.5 to 3.0MPa.

[0057] The nanofiltration membrane is made of aromatic polyamide; the reverse osmosis membrane tube is made of composite polyamide.

[0058] The present invention sequentially performs nanofiltration and one-stage reverse osmosis treatment in the first filter bottle, and utilizes different interception characteristics and pressure conditions to achieve deep removal of impurities in purified concentrated water. The molecular weight cutoff of the nanofiltration membrane is 200 to 1000 Da, which can effectively intercept divalent ions, some monovalent ions, and organic matter with a relative molecular mass in this range, and preliminarily reduce the impurity content in the water. Subsequently, the one-stage reverse osmosis treatment with an operating pressure of 1.5 to 3.0 MPa, relying on the reverse osmosis membrane tube made of composite polyamide material, can almost intercept all remaining ions, microorganisms and organic matter, greatly reducing the conductivity and impurity content of the one-stage concentrated water, so that its water quality reaches higher standards and meets the strict requirements of subsequent treatment or reuse.

[0059] The combination of nanofiltration and reverse osmosis achieves precise separation and concentration of substances in purified concentrated water. Nanofiltration selectively separates different ions and organic matter based on the screening effect and charge effect; reverse osmosis further strengthens the interception of various substances, so that the impurity concentration on the concentrated water side continues to increase, and the water production side obtains high-purity first-stage concentrated water. This separation and concentration effect can not only recycle high-purity water resources, but also concentrate impurities in concentrated water, which is convenient for subsequent unified treatment of concentrated water, improving resource utilization efficiency and treatment effect.

[0060] The present invention adopts nanofiltration membrane made of aromatic polyamide and reverse osmosis membrane tube made of composite polyamide, which has good chemical stability, mechanical strength and anti-pollution performance, can operate stably for a long time in a complex acidic wastewater environment, reduces the frequency of membrane replacement, and reduces equipment maintenance costs.

[0061] Preferably, in the step (S04), the first-stage concentrated concentrated water is first introduced into the second filter bottle, and nanofiltration and first-stage two-stage reverse osmosis treatment are performed to obtain first-stage two-stage concentrated water product and concentrated water, and the first-stage two-stage concentrated water product is discharged into the final water product tank; the retention molecular weight of the nanofiltration treatment is 200 to 1000Da, and the operating pressure is 0.6 to 1.6MPa; the operating pressure of the first-stage two-stage reverse osmosis treatment is 1.8 to 3.2MPa.

[0062] The present invention introduces the first-stage concentrated concentrated water into the second filter bottle for nanofiltration and first-stage two-stage reverse osmosis treatment to further remove impurities in the water. The nanofiltration membrane has a molecular weight cutoff of 200 to 1000 Da and an operating pressure of 0.6-1.6 MPa, which can re-retain the divalent ions, some stubborn organic matter and a small amount of monovalent ions remaining in the first-stage one-stage concentrated concentrated water. Subsequently, the first-stage two-stage reverse osmosis treatment under an operating pressure of 1.8 to 3.2 MPa can more thoroughly intercept the remaining various ions, microorganisms and organic matter, further reduce the conductivity of the first-stage two-stage concentrated water, significantly reduce the impurity content, and achieve a higher and more stable water quality, meeting higher-level reuse or subsequent treatment requirements.

[0063] Preferably, in the step (S05), the first-stage two-stage concentrated concentrated water is first introduced into the third filter bottle, and nanofiltration and first-stage three-stage reverse osmosis treatment are performed to obtain first-stage three-stage concentrated product water and concentrated water, and the first-stage three-stage concentrated product water is discharged into the final product water tank; the retention molecular weight of the nanofiltration treatment is 200 to 1000Da, and the operating pressure is 0.7 to 1.7MPa; the operating pressure of the first-stage three-stage reverse osmosis treatment is 2.0 to 3.5MPa.

[0064] The present invention introduces the first-stage and second-stage concentrated water into the third filter bottle, and deeply removes impurities in the water through nanofiltration and first-stage and third-stage reverse osmosis treatment. The nanofiltration membrane with a molecular weight cutoff of 200 to 1000 Da can intercept the remaining divalent ions, a small amount of organic matter that has not been removed, and part of the monovalent ions again at an operating pressure of 0.7 to 1.7 MPa. Then, the first-stage and third-stage reverse osmosis treatment at an operating pressure of 2.0 to 3.5 MPa greatly reduces the conductivity of the first-stage and third-stage concentrated water.

[0065] Preferably, in the step (S06), the first-stage three-stage concentrated concentrated water is first introduced into the first-stage accelerating tube, and based on the changes in the diameters of the first-stage accelerating tube, the second-stage accelerating tube and the third-stage accelerating tube, a pressure difference is generated in the water flow in the tube, and the water flow rate is increased to 1.5 to 2.5 times the initial flow rate, and then the accelerated first-stage three-stage concentrated concentrated water is introduced into the fourth filter bottle for secondary reverse osmosis treatment; the operating pressure of the secondary reverse osmosis treatment is 3.0 to 5.0 MPa.

[0066] The present invention generates a pressure difference by changing the diameter of the first-stage accelerating tube, the second-stage accelerating tube and the third-stage accelerating tube, thereby increasing the water flow rate to 1.5 to 2.5 times the initial flow rate. The high-speed water flow can significantly enhance the mass transfer efficiency, make the impurities in the water contact more fully with the second-stage reverse osmosis membrane, speed up the separation speed of ions and impurities, greatly shorten the time required for the second-stage reverse osmosis treatment, increase the treatment capacity per unit time, and improve the operation efficiency of the entire acid wastewater treatment system.

[0067] The present invention performs secondary reverse osmosis treatment at a high operating pressure of 3.0-5.0 MPa, and with the accelerated water flow, it can more effectively overcome the osmotic pressure of the solute and deeply intercept the trace impurities remaining in the primary three-stage concentrated concentrated water. Even extremely tiny ions, microorganisms and organic matter are difficult to pass through the reverse osmosis membrane, so that the purity of the secondary concentrated water reaches an extremely high level.

[0068] The accelerated and efficient mass transfer makes the reverse osmosis process more efficient. When achieving the same treatment effect, compared with the treatment under conventional flow rate and pressure conditions, the overall operation time is shortened and the energy consumption of the equipment is reduced.

[0069] High-speed water flow reduces the deposition and adhesion of impurities on the surface of the reverse osmosis membrane to a certain extent, reducing the risk of membrane contamination. The reduction of membrane contamination means that the cleaning frequency of the reverse osmosis membrane is reduced and the replacement cycle is extended, which not only saves the cost of cleaning and replacing the membrane, but also reduces the downtime caused by equipment maintenance, ensures the continuous and stable operation of the entire treatment system, and extends the service life of the equipment.

[0070] The present invention has the following beneficial effects:

[0071] (1) Through multi-step membrane treatment processes, such as ultrafiltration, nanofiltration and reverse osmosis, impurities such as suspended matter, colloids, organic matter, various ions and microorganisms in acidic wastewater can be effectively removed. For example, ultrafiltration can intercept large molecular organic matter and microorganisms, nanofiltration has a good removal effect on divalent ions and some organic matter, and reverse osmosis can remove almost all ions and residual impurities, so that the final water quality reaches a high standard and meets the requirements of production reuse or safe discharge. In terms of conductivity indicators, from the initial high conductivity of acidic wastewater, after multi-step treatment, the final water conductivity can be lower than 1μS / cm, which effectively reduces the content of dissolved solids in water.

[0072] (2) The entire process is centered on full membrane treatment, which removes impurities while concentrating the acid in the acidic wastewater. The membrane separation process at each stage is carried out in a targeted manner according to the different characteristics of the acid and impurities, so that the acid is enriched in the concentrated water, the acid concentration is increased, the acid is purified and concentrated, and conditions are created for the recycling of the acid.

[0073] (3) The produced water and concentrated water are introduced into the subsequent treatment or reuse stage, especially the secondary concentrated produced water that meets the reuse standards is introduced into the final produced water tank for production reuse, which greatly improves the utilization rate of water resources and reduces the use of fresh water resources, conforms to the concept of sustainable development, and reduces the water cost of the enterprise.

[0074] (4) The cyclic ultrafiltration process can be treated multiple times according to the water quality conditions to ensure the stability of the ultrafiltration water quality; the heat exchange component adjusts the temperature to create suitable conditions for subsequent purification and membrane treatment, thereby improving the treatment efficiency; the first-stage acceleration tube accelerates the concentrated water, enhancing the mass transfer efficiency during the subsequent second-stage reverse osmosis treatment and improving the treatment capacity of the overall system. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0076] Figure 2 It is a schematic diagram of the main framework of the present invention;

[0077] Figure 3 It is a schematic diagram of the raw water tank of the present invention;

[0078] Figure 4 It is a schematic diagram of the spiral tube of the present invention;

[0079] Figure 5 is a schematic diagram of a cache water tank of the present invention;

[0080] Figure 6 is a schematic diagram of a drive motor of the present invention;

[0081] Figure 7 is a schematic diagram of a first water production tank of the present invention;

[0082] Figure 8 is a schematic diagram of the heat-insulating shell of the present invention;

[0083] Fig. 9 is a schematic diagram of a heating ring of the present invention;

[0084] Fig.10 is a schematic diagram of a heat funnel of the present invention;

[0085] Fig.11 is a schematic diagram of an insulating housing of the present invention;

[0086] Fig.12 is a schematic diagram of a liquid level ball bar of the present invention;

[0087] Fig.13 is a schematic diagram of a nanofiltration reverse osmosis assembly of the present invention;

[0088] Fig.14 is a schematic diagram of a first filter bottle of the present invention;

[0089] Fig.15 is a schematic diagram of an acceleration assembly of the present invention;

[0090] Fig.16 is a schematic diagram of a separation assembly of the present invention;

[0091] Fig.17 It is a schematic diagram of the wastewater treatment process of the present invention;

[0092] Fig.18 It is a schematic diagram of the overall process of the present invention.

[0093] The markings in the attached drawings are: 100, main frame; 101, raw water tank; 1011, water inlet pipe; 1012, first guide pipe; 1013, water inlet pump; 1014, second guide pipe; 1015, spiral tube; 1016, magnetic column; 1017, sedimentation barrel; 1018, filter plate; 1019, pH and flow detection ring; 102, first water production tank; 1021, eighth guide pipe; 1022, booster pump; 1023, ninth guide pipe; 103, final concentrated water tank; 104, final water production tank; 200, first safety filter; 201, third guide pipe; 202, buffer water tank ; 203, the fourth guide tube; 204, the circulation pump; 205, the fifth guide tube; 206, the second security filter; 2061, the tenth guide tube; 2062, the high-pressure pump; 2063, the eleventh guide tube; 300, the ultrafiltration component; 301, the membrane shell; 3011, the three-way valve; 302, the sixth guide tube; 3021, the pressure gauge; 3022, the temperature sensor; 3023, the flow meter; 3024, the control valve; 3025, the seventh guide tube; 303, the fixed frame; 304, the ultrafiltration pipeline; 305, the transmission column; 306, the drive motor; 400, the heat exchange component; 401, the first heat exchange row; 402, insulation shell; 403, first gas exchange tube; 4031, heating ring; 4032, second gas exchange tube; 404, second heat exchange row; 4041, twelfth flow guide tube; 405, ball valve; 4051, thirteenth flow guide tube; 406, heat funnel; 4061, liquid exchange tube; 500, purification component; 501, insulation shell; 502, electrode plate; 503, liquid level ball rod; 5031, liquid level display; 504, insulation tube; 5041, first branch pipe; 5042, second branch pipe; 600, nanofiltration reverse osmosis component; 601, first filter bottle; 60 11. the fourteenth flow guide tube; 6012. the nanofiltration membrane; 6013. the liquid conduit; 6014. the first reverse osmosis barrel; 60141. the reverse osmosis membrane tube; 6015. the second reverse osmosis barrel; 602. the second filter bottle; 6021. the fifteenth flow guide tube; 603. the third filter bottle; 6031. the sixteenth flow guide tube; 700. the acceleration assembly; 701. the acceleration bracket; 702. the first acceleration tube; 703. the second acceleration tube; 704. the third acceleration tube; 7041. the seventeenth flow guide tube; 800. the separation assembly; 801. the fourth filter bottle; 8011. the first separation tube; 8012. the second separation tube. DETAILED DESCRIPTION

[0094] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0095] The full membrane treatment device for purifying and concentrating the acid in the acidic wastewater includes: Figure 2 The main frame 100 shown in FIG. 1 has a main frame 100, and a main frame 100 has a main frame 100 disposed on one side thereof. Figure 3 The raw water tank 101 shown in FIG. 1 has a side provided with a Figure 1 The first security filter 200 shown in FIG. 1 has an ultrafiltration component 300 disposed on one side of the first security filter 200 away from the raw water tank 101, and a filter element 300 disposed below the side of the ultrafiltration component 300 away from the first security filter 200. Figure 8 The heat exchange component 400 shown in FIG. 4 is provided with a heat exchange component 400 on one side close to the ultrafiltration component 300. Fig.11 The purification component 500 shown in FIG. 1 is provided with a side of the purification component 500 away from the heat exchange component 400. Fig.13 The nanofiltration reverse osmosis component 600 shown in FIG. 1 is provided with a side of the nanofiltration reverse osmosis component 600 away from the purification component 500. Fig.15 The acceleration assembly 700 shown in FIG. 1 is provided with a side of the acceleration assembly 700 away from the nanofiltration reverse osmosis assembly 600. Fig.16 The separation assembly 800 is shown.

[0096] A water inlet pipe 1011 is provided on one side of the raw water tank 101, a first flow guide pipe 1012 is provided on the side of the raw water tank 101 away from the water inlet pipe 1011, an inlet pump 1013 is provided on the end of the first flow guide pipe 1012 away from the raw water tank 101, a second flow guide pipe 1014 is provided on the side of the inlet pump 1013 away from the first flow guide pipe 1012, and the end of the second flow guide pipe 1014 away from the inlet pump 1013 is connected to the first safety filter 200.

[0097] like Figure 3 The raw water tank 101 shown includes Figure 4 The spiral tube 1015 shown is arranged on the top of the raw water tank 101, a magnetic column 1016 is arranged on the inner side of the spiral tube 1015, a sedimentation barrel 1017 is arranged at the bottom end of the spiral tube 1015, a filter plate 1018 is arranged at the bottom end of the sedimentation barrel 1017, and a pH and flow detection ring 1019 is arranged on the outer side of the filter plate 1018.

[0098] The bottom end of the first safety filter 200 is provided with a third flow guide tube 201. The bottom end of the third flow guide tube 201 is provided with Figure 5 The cache water tank 202 shown in the figure has a fourth flow pipe 203 arranged on one side of the cache water tank 202, a circulating pump 204 is arranged on the side of the fourth flow pipe 203 away from the cache water tank 202, a fifth flow pipe 205 is arranged on the end of the circulating pump 204 away from the fourth flow pipe 203, a three-way valve 3011 is arranged on the end of the fifth flow pipe 205 away from the circulating pump 204, and the three-way valve 3011 is arranged above the ultrafiltration component 300.

[0099] The ultrafiltration assembly 300 includes a membrane shell 301, which is disposed on one side of the first security filter 200. A fixing frame 303 is disposed on the inner side of the membrane shell 301. A plurality of ultrafiltration pipes 304 are disposed on the inner side of the fixing frame 303. A transmission column 305 is fixedly disposed at the center of the fixing frame 303. Figure 6 A driving motor 306 is provided at the bottom end of the driving column 305 , and an output end of the driving motor 306 is fixedly connected to the driving column 305 .

[0100] A sixth flow guide tube 302 is provided on one side of the membrane shell 301, a pressure gauge 3021 is provided on the side of the sixth flow guide tube 302, a temperature sensor 3022 is provided on the side of the pressure gauge 3021 away from the membrane shell 301, the bottom end of the temperature sensor 3022 is connected to the sixth flow guide tube 302, a flow meter 3023 is provided on the side of the temperature sensor 3022 away from the pressure gauge 3021, the bottom end of the flow meter 3023 is connected to the sixth flow guide tube 302, a control valve 3024 is provided on the end of the sixth flow guide tube 302 away from the membrane shell 301, a seventh flow guide tube 3025 is provided on the end of the control valve 3024 away from the sixth flow guide tube 302, and a valve 3026 is provided on the end of the seventh flow guide tube 3025 away from the control valve 3024. Figure 7 The first water production tank 102 shown in the figure has an eighth flow guide pipe 1021 disposed on one side of the first water production tank 102, a booster pump 1022 disposed on the side of the eighth flow guide pipe 1021 away from the first water production tank 102, a ninth flow guide pipe 1023 disposed on the end of the booster pump 1022 away from the eighth flow guide pipe 1021, a second safety filter 206 disposed on the end of the ninth flow guide pipe 1023 away from the booster pump 1022, a tenth flow guide pipe 2061 disposed on the end of the second safety filter 206 away from the ninth flow guide pipe 1023, a high-pressure pump 2062 disposed on the end of the tenth flow guide pipe 2061 away from the second safety filter 206, an eleventh flow guide pipe 2063 disposed on the end of the high-pressure pump 2062 away from the tenth flow guide pipe 2061, and the eleventh flow guide pipe 2063 and the first flow guide pipe 2063 are connected to each other as shown in the figure. Figure 8 The heat exchange components 400 are shown connected.

[0101] like Figure 8 The heat exchange assembly 400 shown includes an insulating shell 402, which is fixedly connected to the main frame 100. A first heat exchange row 401 is provided on one side of the insulating shell 402, and a second heat exchange row 404 is provided on the side of the insulating shell 402 away from the first heat exchange row 401. A twelfth flow guide pipe 4041 is provided on the side of the second heat exchange row 404 away from the insulating shell 402, and a ball valve 405 is provided on the side of the twelfth flow guide pipe 4041 away from the second heat exchange row 404. A thirteenth flow guide pipe 4051 is provided on the end of the ball valve 405 away from the twelfth flow guide pipe 4041, and the thirteenth flow guide pipe 4051 is connected to the thirteenth flow guide pipe 4051. Fig.11 The purification components 500 are shown connected.

[0102] A heat funnel 406 is provided inside the heat-insulating shell 402. Fig.10 A plurality of liquid exchange tubes 4061 are provided in the middle of the heat funnel 406 shown, one end of the liquid exchange tube 4061 is connected to the first heat exchange row 401, and one end of the liquid exchange tube 4061 away from the first heat exchange row 401 is connected to the second heat exchange row 404;

[0103] A first gas exchange pipe 403 is provided on one side of the top of the hot funnel 406. Fig. 9 A heating ring 4031 is provided on the side of the first gas exchange tube 403 , the bottom end of the first gas exchange tube 403 is connected to the bottom end of the heat funnel 406 , and a second gas exchange tube 4032 is provided on the side of the heat funnel 406 away from the first gas exchange tube 403 .

[0104] like Fig.11 The purification assembly 500 shown includes an insulating shell 501, which is fixedly connected to the main frame 100. The side of the insulating shell 501 is provided with an electrode plate 502. The top of the insulating shell 501 is slidably connected to the main frame 100. Fig.12 The liquid level ball rod 503 shown in the figure has a liquid level display 5031 disposed at the top end thereof, and an insulating tube 504 disposed on one side of the insulating shell 501 .

[0105] like Fig.13 The nanofiltration reverse osmosis assembly 600 shown in the figure includes a first filter bottle 601, which is arranged on one side of an insulating tube 504, and a first branch pipe 5041 is arranged on the side of the insulating tube 504 close to the first filter bottle 601, and the end of the first branch pipe 5041 away from the insulating tube 504 is connected to the first filter bottle 601, and a fourteenth flow guide pipe 6011 is arranged on the top of the first filter bottle 601, and a second filter bottle 602 is arranged on the end of the fourteenth flow guide pipe 6011 away from the first filter bottle 601, and the insulating tube 504 is close to the second filter bottle. A second branch pipe 5042 is provided on one side of the bottle 602, and an end of the second branch pipe 5042 away from the insulating tube 504 is connected to the second filter bottle 602, a fifteenth flow guide pipe 6021 is provided on the top of the second filter bottle 602, a third filter bottle 603 is provided on the end of the fifteenth flow guide pipe 6021 away from the second filter bottle 602, an end of the insulating tube 504 away from the insulating housing 501 is connected to the third filter bottle 603, a sixteenth flow guide pipe 6031 is provided on the top of the third filter bottle 603, and the sixteenth flow guide pipe 6031 is connected to the filter bottle 6031. Fig.15 The accelerating assembly 700 is shown connected.

[0106] like Fig.14The top of the first filter bottle 601 shown is provided with a nanofiltration membrane 6012, a plurality of liquid conduits 6013 are provided below the nanofiltration membrane 6012, a first reverse osmosis barrel 6014 is provided at the bottom end of the liquid conduits 6013, a plurality of reverse osmosis membrane tubes 60141 are provided on the inner side of the first reverse osmosis barrel 6014, and a second reverse osmosis barrel 6015 is provided below the first reverse osmosis barrel 6014.

[0107] like Fig.15 The acceleration assembly 700 shown in the figure includes an acceleration bracket 701, which is arranged on the main frame 100. A primary acceleration tube 702 is arranged on the inner side of the acceleration bracket 701. A secondary acceleration tube 703 is arranged at one end of the primary acceleration tube 702. A tertiary acceleration tube 704 is arranged at one end of the secondary acceleration tube 703 away from the primary acceleration tube 702. A seventeenth guide tube 7041 is arranged at one end of the tertiary acceleration tube 704 away from the secondary acceleration tube 703. The seventeenth guide tube 7041 is connected to the Fig.16 The separation components 800 are shown connected.

[0108] like Fig.16 The separation assembly 800 shown includes a fourth filter bottle 801, which is fixedly connected to the main frame 100. A first separation tube 8011 is arranged on the top side of the fourth filter bottle 801, and the end of the first separation tube 8011 away from the fourth filter bottle 801 is connected to the final concentrated water tank 103. A second separation tube 8012 is arranged on the bottom side of the fourth filter bottle 801, and the end of the second separation tube 8012 away from the fourth filter bottle 801 is connected to the final produced water tank 104.

[0109] The full membrane treatment process for purifying and concentrating the acid in the acidic wastewater includes the following steps:

[0110] (S01) introducing acidic wastewater into a raw water tank, and then pumping the acidic wastewater into a first security filter, and after filtration, pumping the filtered water into an ultrafiltration component for ultrafiltration treatment, and obtaining ultrafiltration product water and concentrated water after ultrafiltration, discharging the ultrafiltration concentrated water, and introducing the ultrafiltration product water back into the raw water tank for cyclic ultrafiltration;

[0111] (S02) introducing the ultrafiltration product water after the cyclic ultrafiltration into the heat exchange component, adjusting the temperature of the ultrafiltration concentrated water, and then introducing the ultrafiltration product water after the temperature adjustment into the purification component for purification treatment, obtaining purified product water and concentrated water after purification, and discharging the purified concentrated water;

[0112] (S03) introducing the purified produced water into the first filter bottle, performing nanofiltration and one-stage reverse osmosis treatment to obtain one-stage concentrated produced water and concentrated water, and discharging the one-stage concentrated produced water into the final produced water tank;

[0113] (S04) introducing the concentrated water from the first stage into the second filter bottle, performing nanofiltration and the first stage and second stage reverse osmosis treatment to obtain the first stage and second stage concentrated water and concentrated water, and discharging the first stage and second stage concentrated water into the final water production tank;

[0114] (S05) introducing the concentrated water from the first stage and second stage into the third filter bottle, performing nanofiltration and first stage and third stage reverse osmosis treatment to obtain the first stage and third stage concentrated water and concentrated water, and discharging the first stage and third stage concentrated water into the final water production tank;

[0115] (S06) The first-stage three-stage concentrated concentrated water is introduced into the first-stage acceleration tube for acceleration treatment, and then the first-stage three-stage concentrated concentrated water after the acceleration treatment is introduced into the fourth filter bottle for secondary reverse osmosis treatment to obtain secondary concentrated water and concentrated water, and the secondary concentrated water is introduced into the final water production tank, and the secondary concentrated concentrated water is discharged into the final concentrated water tank to achieve the recycling of acidic wastewater.

[0116] In step (S01), the acidic wastewater is first introduced into Fig.18 The raw water tank shown in the figure is then pumped into the first security filter, and after filtration, the filtered water is pumped into the ultrafiltration component to perform the following steps: Fig.17 The ultrafiltration treatment shown in the figure obtains ultrafiltration product water and concentrated water, the ultrafiltration concentrated water is discharged, and the ultrafiltration product water is led back to the raw water tank, and the ultrafiltration treatment is carried out for 2 to 5 cycles.

[0117] In step (S02), the ultrafiltration product water after circulating ultrafiltration is first introduced into the heat exchange component, the temperature of the ultrafiltration concentrated water is increased to 25-40°C, and then the ultrafiltration product water after temperature adjustment is introduced into the purification component, and purified using an electric field of 500-1000V / m to obtain purified product water and concentrated water, and the purified concentrated water is discharged.

[0118] In step (S03), the purified product water is first introduced into the first filter bottle, and nanofiltration and one-stage reverse osmosis treatment are performed to obtain one-stage concentrated product water and concentrated water, and the one-stage concentrated product water is discharged into the final product water tank; the molecular weight cutoff of the nanofiltration treatment is 200-1000Da, and the operating pressure is 0.5-1.5MPa; the operating pressure of the one-stage reverse osmosis treatment is 1.5-3.0MPa.

[0119] In step (S04), the first-stage concentrated concentrated water is first introduced into the second filter bottle for nanofiltration and first-stage two-stage reverse osmosis treatment to obtain first-stage two-stage concentrated water and concentrated water, and the first-stage two-stage concentrated water is discharged into the final water tank; the molecular weight cutoff of the nanofiltration treatment is 200 to 1000Da, and the operating pressure is 0.6 to 1.6MPa; the operating pressure of the first-stage two-stage reverse osmosis treatment is 1.8 to 3.2MPa.

[0120] In step (S05), the first-stage two-stage concentrated concentrated water is first introduced into the third filter bottle for nanofiltration and first-stage three-stage reverse osmosis treatment to obtain first-stage three-stage concentrated water and concentrated water, and the first-stage three-stage concentrated water is discharged into the final water production tank; the retention molecular weight of the nanofiltration treatment is 200-1000Da, and the operating pressure is 0.7-1.7MPa; the operating pressure of the first-stage three-stage reverse osmosis treatment is 2.0-3.5MPa.

[0121] In step (S06), the first-stage three-stage concentrated concentrated water is first introduced into the first-stage accelerating tube. Based on the changes in the diameters of the first-stage accelerating tube, the second-stage accelerating tube and the third-stage accelerating tube, a pressure difference is generated in the water flow in the tube, and the water flow rate is increased to 1.5 to 2.5 times the initial flow rate. The accelerated first-stage three-stage concentrated concentrated water is then introduced into the fourth filter bottle for secondary reverse osmosis treatment; the operating pressure of the secondary reverse osmosis treatment is 3.0 to 5.0 MPa.

[0122] Embodiment 1:

[0123] The full membrane treatment process for purifying and concentrating the acid in the acidic wastewater includes the following steps:

[0124] (S01) introducing acidic wastewater into a raw water tank, and then pumping the acidic wastewater into a first security filter, and after filtration, pumping the filtered water into an ultrafiltration component for ultrafiltration treatment, and obtaining ultrafiltration product water and concentrated water after ultrafiltration, discharging the ultrafiltration concentrated water, and introducing the ultrafiltration product water back into the raw water tank for cyclic ultrafiltration;

[0125] (S02) introducing the ultrafiltration product water after the cyclic ultrafiltration into the heat exchange component, adjusting the temperature of the ultrafiltration concentrated water, and then introducing the ultrafiltration product water after the temperature adjustment into the purification component for purification treatment, obtaining purified product water and concentrated water after purification, and discharging the purified concentrated water;

[0126] (S03) introducing the purified produced water into the first filter bottle, performing nanofiltration and one-stage reverse osmosis treatment to obtain one-stage concentrated produced water and concentrated water, and discharging the one-stage concentrated produced water into the final produced water tank;

[0127] (S04) introducing the concentrated water from the first stage into the second filter bottle, performing nanofiltration and the first stage and second stage reverse osmosis treatment to obtain the first stage and second stage concentrated water and concentrated water, and discharging the first stage and second stage concentrated water into the final water production tank;

[0128] (S05) introducing the concentrated water from the first stage and second stage into the third filter bottle, performing nanofiltration and first stage and third stage reverse osmosis treatment to obtain the first stage and third stage concentrated water and concentrated water, and discharging the first stage and third stage concentrated water into the final water production tank;

[0129] (S06) The first-stage three-stage concentrated concentrated water is introduced into the first-stage acceleration tube for acceleration treatment, and then the first-stage three-stage concentrated concentrated water after the acceleration treatment is introduced into the fourth filter bottle for secondary reverse osmosis treatment to obtain secondary concentrated water and concentrated water, and the secondary concentrated water is introduced into the final water production tank, and the secondary concentrated concentrated water is discharged into the final concentrated water tank to achieve the recycling of acidic wastewater.

[0130] Taking a certain pigment production plant as an example, the daily amount of acidic wastewater generated is 500t / d, with an acidity of 1.72%. The main components are sulfuric acid and sulfates. The sulfate ion concentration is tested to be 3g / L, the total concentration of heavy metal ions (such as lead, mercury, etc.) is 0.1g / L, and the total concentration of calcium and magnesium ions is 0.08g / L.

[0131] The acidic wastewater treatment data in this example are shown in the following table:

[0132] Table 1

[0133]

[0134] In step (S01), the acidic wastewater is first introduced into the raw water tank, and then the acidic wastewater in the raw water tank is pumped into the first security filter. After filtration, the filtered water is pumped into the ultrafiltration component for ultrafiltration treatment to obtain ultrafiltration product water and concentrated water. The ultrafiltration concentrated water is discharged, and the ultrafiltration product water is introduced back to the raw water tank for two cycles of ultrafiltration treatment.

[0135] The magnetic column absorbs magnetic impurities in the wastewater, and the adsorption rate of magnetic impurities can reach more than 95%; the sedimentation barrel uses gravity sedimentation to make large particles settle to the bottom, and the sedimentation efficiency can reach 90%. The filter plate further intercepts fine impurities, and the pH and flow detection ring monitors the water quality in real time. The wastewater that has been initially purified is pumped into the first security filter by the water inlet pump. The PP melt-blown filter element with a precision of 5 microns is used to effectively intercept suspended matter, colloids and other impurities, and the removal rate of suspended matter can reach 98%.

[0136] The ultrafiltration component uses an ultrafiltration membrane made of polyvinylidene fluoride (PVDF) with a molecular weight cutoff of 1000 Daltons. The operating pressure is maintained at 0.13 MPa, and the retention rate of large molecular organic matter can reach more than 85%.

[0137] The ultrafiltration concentrated water is discharged outside, and the ultrafiltration product water flows back to the raw water tank for the second ultrafiltration treatment. The removal rate of heavy metal ions can reach more than 90%, reducing the heavy metal ion concentration to below 0.05g / L.

[0138] In step (S02), the ultrafiltration water produced after the circulating ultrafiltration is first introduced into the heat exchange component, the temperature of the ultrafiltration concentrated water is increased to 25°C, and then the ultrafiltration water produced after temperature adjustment is introduced into the purification component, and purified using an electric field of 500V / m to obtain purified water and concentrated water, and the purified concentrated water is discharged.

[0139] The heat exchange component uses the principles of heat conduction and convection to raise the water temperature to 25°C, and applies an electric field of 500V / m through the electrode plate to remove high hardness cations through electrodialysis. Under this condition, the removal rate of calcium and magnesium ions can reach more than 95%, reducing the concentration of calcium and magnesium ions to below 0.01g / L.

[0140] In step (S03), the purified product water is first introduced into the first filter bottle, and nanofiltration and one-stage reverse osmosis treatment are performed to obtain one-stage concentrated product water and concentrated water, and the one-stage concentrated product water is discharged into the final product water tank; the molecular weight cutoff of the nanofiltration treatment is 200Da, and the operating pressure is 0.5MPa; the operating pressure of the one-stage reverse osmosis treatment is 1.5MPa.

[0141] The nanofiltration membrane is made of aromatic polyamide, with a molecular weight cutoff of 200Da and an operating pressure of 0.5MPa. The removal rate of divalent ions can reach more than 80%, and the removal rate of organic matter with a molecular weight of 200 to 1000 Daltons can reach 75%. Then the first-stage reverse osmosis treatment is carried out. The reverse osmosis membrane tube is made of composite polyamide and the operating pressure is 1.5MPa to further remove the remaining ions and organic matter.

[0142] In step (S04), the first-stage concentrated concentrated water is first introduced into the second filter bottle for nanofiltration and first-stage two-stage reverse osmosis treatment to obtain first-stage two-stage concentrated water and concentrated water, and the first-stage two-stage concentrated water is discharged into the final water tank; the molecular weight cutoff of the nanofiltration treatment is 200Da, and the operating pressure is 0.6MPa; the operating pressure of the first-stage two-stage reverse osmosis treatment is 1.8MPa.

[0143] The nanofiltration operating pressure is increased to 0.6MPa, and the interception characteristics remain unchanged, and the residual impurities are removed again. Then the first-stage two-stage reverse osmosis treatment is carried out, and the operating pressure is 1.8MPa, and the comprehensive removal rate of the remaining impurities can reach more than 70%.

[0144] In step (S05), the first-stage two-stage concentrated concentrated water is first introduced into the third filter bottle for nanofiltration and first-stage three-stage reverse osmosis treatment to obtain first-stage three-stage concentrated water and concentrated water, and the first-stage three-stage concentrated water is discharged into the final water tank; the retention molecular weight of the nanofiltration treatment is 200Da, and the operating pressure is 0.7MPa; the operating pressure of the first-stage three-stage reverse osmosis treatment is 2.0MPa.

[0145] The nanofiltration operating pressure is 0.7MPa, and the reverse osmosis operating pressure is 2.0MPa. After treatment, the removal rate of trace impurities can reach more than 65%.

[0146] In step (S06), the first-stage three-stage concentrated concentrated water is first introduced into the first-stage accelerating tube. Based on the changes in the diameters of the first-stage accelerating tube, the second-stage accelerating tube and the third-stage accelerating tube, a pressure difference is generated in the water flow in the tube, and the water flow rate is increased to 1.5 times the initial flow rate. The accelerated first-stage three-stage concentrated concentrated water is then introduced into the fourth filter bottle for secondary reverse osmosis treatment; the operating pressure of the secondary reverse osmosis treatment is 3.0 MPa.

[0147] The initial velocity of the fluid increases rapidly from 20m / s to 35m / s. Under high-speed water flow, the removal rate of extremely trace impurities can reach more than 60%.

[0148] Embodiment 2:

[0149] The full membrane treatment process for purifying and concentrating the acid in the acidic wastewater includes the following steps:

[0150] (S01) introducing acidic wastewater into a raw water tank, and then pumping the acidic wastewater into a first security filter, and after filtration, pumping the filtered water into an ultrafiltration component for ultrafiltration treatment, and obtaining ultrafiltration product water and concentrated water after ultrafiltration, discharging the ultrafiltration concentrated water, and introducing the ultrafiltration product water back into the raw water tank for cyclic ultrafiltration;

[0151] (S02) introducing the ultrafiltration product water after the cyclic ultrafiltration into the heat exchange component, adjusting the temperature of the ultrafiltration concentrated water, and then introducing the ultrafiltration product water after the temperature adjustment into the purification component for purification treatment, obtaining purified product water and concentrated water after purification, and discharging the purified concentrated water;

[0152] (S03) introducing the purified produced water into the first filter bottle, performing nanofiltration and one-stage reverse osmosis treatment to obtain one-stage concentrated produced water and concentrated water, and discharging the one-stage concentrated produced water into the final produced water tank;

[0153] (S04) introducing the concentrated water from the first stage into the second filter bottle, performing nanofiltration and the first stage and second stage reverse osmosis treatment to obtain the first stage and second stage concentrated water and concentrated water, and discharging the first stage and second stage concentrated water into the final water production tank;

[0154] (S05) introducing the concentrated water from the first stage and second stage into the third filter bottle, performing nanofiltration and first stage and third stage reverse osmosis treatment to obtain the first stage and third stage concentrated water and concentrated water, and discharging the first stage and third stage concentrated water into the final water production tank;

[0155] (S06) The first-stage three-stage concentrated concentrated water is introduced into the first-stage acceleration tube for acceleration treatment, and then the first-stage three-stage concentrated concentrated water after the acceleration treatment is introduced into the fourth filter bottle for secondary reverse osmosis treatment to obtain secondary concentrated water and concentrated water, and the secondary concentrated water is introduced into the final water production tank, and the secondary concentrated concentrated water is discharged into the final concentrated water tank to achieve the recycling of acidic wastewater.

[0156] Taking a certain pigment production plant as an example, the daily amount of acidic wastewater generated is 500t / d, with an acidity of 1.72%. The main components are sulfuric acid and sulfates. The sulfate ion concentration is tested to be 3g / L, the total concentration of heavy metal ions (such as lead, mercury, etc.) is 0.1g / L, and the total concentration of calcium and magnesium ions is 0.08g / L.

[0157] The acidic wastewater treatment data in this example are shown in the following table:

[0158]

[0159] In step (S01), the acidic wastewater is first introduced into the raw water tank, and then the acidic wastewater in the raw water tank is pumped into the first security filter. After filtration, the filtered water is pumped into the ultrafiltration component for ultrafiltration treatment to obtain ultrafiltration product water and concentrated water. The ultrafiltration concentrated water is discharged, and the ultrafiltration product water is introduced back to the raw water tank, and the ultrafiltration treatment is repeated 5 times.

[0160] The magnetic column absorbs magnetic impurities in the wastewater, and the adsorption rate of magnetic impurities can reach more than 95%; the sedimentation barrel uses gravity sedimentation to make large particles settle to the bottom, and the sedimentation efficiency can reach 90%. The filter plate further intercepts fine impurities, and the pH and flow detection ring monitors the water quality in real time. The wastewater that has been initially purified is pumped into the first security filter by the water inlet pump. The PP melt-blown filter element with a precision of 5 microns is used to effectively intercept suspended matter, colloids and other impurities, and the removal rate of suspended matter can reach 98%.

[0161] The ultrafiltration component uses an ultrafiltration membrane made of polyvinylidene fluoride (PVDF) with a molecular weight cutoff of 1000 Daltons. The operating pressure is maintained at 0.13 MPa, and the retention rate of large molecular organic matter can reach more than 85%.

[0162] The ultrafiltration concentrated water is discharged externally, and the ultrafiltration product water flows back to the raw water tank and is recycled for 4 ultrafiltration treatments. The removal rate of heavy metal ions can reach more than 92%, reducing the concentration of heavy metal ions to below 0.04g / L.

[0163] In step (S02), the ultrafiltration water produced after the circulating ultrafiltration is first introduced into the heat exchange component, the temperature of the ultrafiltration concentrated water is increased to 40°C, and then the ultrafiltration water produced after temperature adjustment is introduced into the purification component, and purified using an electric field of 1000V / m to obtain purified water and concentrated water, and the purified concentrated water is discharged.

[0164] The heat exchange component uses the principles of heat conduction and convection to raise the water temperature to 40°C, and applies an electric field of 1000V / m through the electrode plate to remove high hardness cations through electrodialysis. Under this condition, the removal rate of calcium and magnesium ions can reach more than 96%, reducing the concentration of calcium and magnesium ions to below 0.008g / L.

[0165] In step (S03), the purified product water is first introduced into the first filter bottle, and nanofiltration and one-stage reverse osmosis treatment are performed to obtain one-stage concentrated product water and concentrated water, and the one-stage concentrated product water is discharged into the final product water tank; the molecular weight cutoff of the nanofiltration treatment is 1000Da, and the operating pressure is 1.5MPa; the operating pressure of the one-stage reverse osmosis treatment is 3.0MPa.

[0166] The nanofiltration membrane is made of aromatic polyamide, with a molecular weight cutoff of 1000Da and an operating pressure of 1.5MPa. The removal rate of divalent ions can reach more than 85%, and the removal rate of organic matter with a molecular weight of 200 to 1000 Daltons can reach 80%. Then the first-stage reverse osmosis treatment is carried out. The reverse osmosis membrane tube is made of composite polyamide and the operating pressure is 3.0MPa to further remove the remaining ions and organic matter.

[0167] In step (S04), the first-stage concentrated concentrated water is first introduced into the second filter bottle for nanofiltration and first-stage two-stage reverse osmosis treatment to obtain first-stage two-stage concentrated water and concentrated water, and the first-stage two-stage concentrated water is discharged into the final water tank; the molecular weight cutoff of the nanofiltration treatment is 1000Da, and the operating pressure is 1.6MPa; the operating pressure of the first-stage two-stage reverse osmosis treatment is 3.2MPa.

[0168] The nanofiltration operating pressure is increased to 1.6MPa, and the interception characteristics remain unchanged, and the residual impurities are removed again. Then the first-stage two-stage reverse osmosis treatment is carried out, and the operating pressure is 3.2MPa, and the comprehensive removal rate of the remaining impurities can reach more than 75%.

[0169] In step (S05), the first-stage two-stage concentrated concentrated water is first introduced into the third filter bottle for nanofiltration and first-stage three-stage reverse osmosis treatment to obtain first-stage three-stage concentrated water and concentrated water, and the first-stage three-stage concentrated water is discharged into the final water tank; the molecular weight cutoff of the nanofiltration treatment is 1000Da, and the operating pressure is 1.7MPa; the operating pressure of the first-stage three-stage reverse osmosis treatment is 3.5MPa.

[0170] The nanofiltration operating pressure is 1.7MPa, and the reverse osmosis operating pressure is 3.5MPa. After treatment, the removal rate of trace impurities can reach more than 70%.

[0171] In step (S06), the first-stage three-stage concentrated concentrated water is first introduced into the first-stage accelerating tube. Based on the changes in the diameters of the first-stage accelerating tube, the second-stage accelerating tube and the third-stage accelerating tube, a pressure difference is generated in the water flow in the tube, and the water flow rate is increased to 2.5 times the initial flow rate. The accelerated first-stage three-stage concentrated concentrated water is then introduced into the fourth filter bottle for secondary reverse osmosis treatment; the operating pressure of the secondary reverse osmosis treatment is 5.0 MPa.

[0172] The initial velocity of the fluid increases rapidly from 20m / s to 50m / s. Under high-speed water flow, the removal rate of extremely trace impurities can reach more than 65%.

[0173] Embodiment 3:

[0174] The full membrane treatment process for purifying and concentrating the acid in the acidic wastewater includes the following steps:

[0175] (S01) introducing acidic wastewater into a raw water tank, and then pumping the acidic wastewater into a first security filter, and after filtration, pumping the filtered water into an ultrafiltration component for ultrafiltration treatment, and obtaining ultrafiltration product water and concentrated water after ultrafiltration, discharging the ultrafiltration concentrated water, and introducing the ultrafiltration product water back into the raw water tank for cyclic ultrafiltration;

[0176] (S02) introducing the ultrafiltration product water after the cyclic ultrafiltration into the heat exchange component, adjusting the temperature of the ultrafiltration concentrated water, and then introducing the ultrafiltration product water after the temperature adjustment into the purification component for purification treatment, obtaining purified product water and concentrated water after purification, and discharging the purified concentrated water;

[0177] (S03) introducing the purified produced water into the first filter bottle, performing nanofiltration and one-stage reverse osmosis treatment to obtain one-stage concentrated produced water and concentrated water, and discharging the one-stage concentrated produced water into the final produced water tank;

[0178] (S04) introducing the concentrated water from the first stage into the second filter bottle, performing nanofiltration and the first stage and second stage reverse osmosis treatment to obtain the first stage and second stage concentrated water and concentrated water, and discharging the first stage and second stage concentrated water into the final water production tank;

[0179] (S05) introducing the concentrated water from the first stage and second stage into the third filter bottle, performing nanofiltration and first stage and third stage reverse osmosis treatment to obtain the first stage and third stage concentrated water and concentrated water, and discharging the first stage and third stage concentrated water into the final water production tank;

[0180] (S06) The first-stage three-stage concentrated concentrated water is introduced into the first-stage acceleration tube for acceleration treatment, and then the first-stage three-stage concentrated concentrated water after the acceleration treatment is introduced into the fourth filter bottle for secondary reverse osmosis treatment to obtain secondary concentrated water and concentrated water, and the secondary concentrated water is introduced into the final water production tank, and the secondary concentrated concentrated water is discharged into the final concentrated water tank to achieve the recycling of acidic wastewater.

[0181] Taking a certain pigment production plant as an example, the daily amount of acidic wastewater generated is 500t / d, with an acidity of 1.72%. The main components are sulfuric acid and sulfates. The sulfate ion concentration is tested to be 3g / L, the total concentration of heavy metal ions (such as lead, mercury, etc.) is 0.1g / L, and the total concentration of calcium and magnesium ions is 0.08g / L.

[0182] The acidic wastewater treatment data in this example are shown in the following table:

[0183] Table 3

[0184]

[0185] In step (S01), the acidic wastewater is first introduced into the raw water tank, and then the acidic wastewater in the raw water tank is pumped into the first security filter. After filtration, the filtered water is pumped into the ultrafiltration component for ultrafiltration treatment to obtain ultrafiltration product water and concentrated water. The ultrafiltration concentrated water is discharged, and the ultrafiltration product water is introduced back to the raw water tank, and three cycles of ultrafiltration treatment are performed.

[0186] The magnetic column absorbs magnetic impurities in the wastewater, and the adsorption rate of magnetic impurities can reach more than 95%; the sedimentation barrel uses gravity sedimentation to make large particles settle to the bottom, and the sedimentation efficiency can reach 90%. The filter plate further intercepts fine impurities, and the pH and flow detection ring monitors the water quality in real time. The wastewater that has been initially purified is pumped into the first security filter by the water inlet pump. The PP melt-blown filter element with a precision of 5 microns is used to effectively intercept suspended matter, colloids and other impurities, and the removal rate of suspended matter can reach 98%.

[0187] The ultrafiltration component uses an ultrafiltration membrane made of polyvinylidene fluoride (PVDF) with a molecular weight cutoff of 1000 Daltons. The operating pressure is maintained at 0.13 MPa, and the retention rate of large molecular organic matter can reach more than 85%.

[0188] The ultrafiltration concentrated water is discharged externally, and the ultrafiltration product water flows back to the raw water tank and is recycled for two ultrafiltration treatments. The removal rate of heavy metal ions can reach more than 91.3%, reducing the heavy metal ion concentration to below 0.045g / L.

[0189] In step (S02), the ultrafiltration water produced after the circulating ultrafiltration is first introduced into the heat exchange component, the temperature of the ultrafiltration concentrated water is increased to 30°C, and then the ultrafiltration water produced after temperature adjustment is introduced into the purification component, and purified using an electric field of 700V / m to obtain purified water and concentrated water, and the purified concentrated water is discharged.

[0190] The heat exchange component uses the principles of heat conduction and convection to raise the water temperature to 30°C, and applies an electric field of 700V / m through the electrode plate to remove high hardness cations through electrodialysis. Under this condition, the removal rate of calcium and magnesium ions can reach more than 95.2%, reducing the concentration of calcium and magnesium ions to below 0.009g / L.

[0191] In step (S03), the purified product water is first introduced into the first filter bottle, and nanofiltration and one-stage reverse osmosis treatment are performed to obtain one-stage concentrated product water and concentrated water, and the one-stage concentrated product water is discharged into the final product water tank; the molecular weight cutoff of the nanofiltration treatment is 600Da, and the operating pressure is 0.8MPa; the operating pressure of the one-stage reverse osmosis treatment is 1.8MPa.

[0192] The nanofiltration membrane is made of aromatic polyamide, with a molecular weight cutoff of 600Da and an operating pressure of 0.8MPa. The removal rate of divalent ions can reach more than 82%, and the removal rate of organic matter with a molecular weight of 200 to 1000 Daltons can reach 78%. Then the first-stage reverse osmosis treatment is carried out. The reverse osmosis membrane tube is made of composite polyamide and the operating pressure is 1.8MPa to further remove the remaining ions and organic matter.

[0193] In step (S04), the first-stage concentrated concentrated water is first introduced into the second filter bottle for nanofiltration and first-stage two-stage reverse osmosis treatment to obtain first-stage two-stage concentrated water and concentrated water, and the first-stage two-stage concentrated water is discharged into the final water tank; the molecular weight cutoff of the nanofiltration treatment is 600Da, and the operating pressure is 1.0MPa; the operating pressure of the first-stage two-stage reverse osmosis treatment is 2.2MPa.

[0194] The nanofiltration operating pressure is increased to 1.0MPa, and the interception characteristics remain unchanged, and the residual impurities are removed again. Then the first-stage two-stage reverse osmosis treatment is carried out, and the operating pressure is 2.2MPa, and the comprehensive removal rate of the remaining impurities can reach more than 73%.

[0195] In step (S05), the first-stage two-stage concentrated concentrated water is first introduced into the third filter bottle for nanofiltration and first-stage three-stage reverse osmosis treatment to obtain first-stage three-stage concentrated water and concentrated water, and the first-stage three-stage concentrated water is discharged into the final water production tank; the retention molecular weight of the nanofiltration treatment is 600Da, and the operating pressure is 1.4MPa; the operating pressure of the first-stage three-stage reverse osmosis treatment is 2.8MPa.

[0196] The nanofiltration operating pressure is 1.4MPa, and the reverse osmosis operating pressure is 2.8MPa. After treatment, the removal rate of trace impurities can reach more than 68%.

[0197] In step (S06), the first-stage three-stage concentrated concentrated water is first introduced into the first-stage accelerating tube. Based on the changes in the diameters of the first-stage accelerating tube, the second-stage accelerating tube and the third-stage accelerating tube, a pressure difference is generated in the water flow in the tube, and the water flow rate is increased to 1.9 times the initial flow rate. The accelerated first-stage three-stage concentrated concentrated water is then introduced into the fourth filter bottle for secondary reverse osmosis treatment; the operating pressure of the secondary reverse osmosis treatment is 3.7MPa.

[0198] The initial velocity of the fluid increases rapidly from 20m / s to 38m / s. Under high-speed water flow, the removal rate of extremely trace impurities can reach more than 65%.

[0199] Embodiment 4:

[0200] The full membrane treatment process for purifying and concentrating the acid in the acidic wastewater includes the following steps:

[0201] (S01) introducing acidic wastewater into a raw water tank, and then pumping the acidic wastewater into a first security filter, and after filtration, pumping the filtered water into an ultrafiltration component for ultrafiltration treatment, and obtaining ultrafiltration product water and concentrated water after ultrafiltration, discharging the ultrafiltration concentrated water, and introducing the ultrafiltration product water back into the raw water tank for cyclic ultrafiltration;

[0202] (S02) introducing the ultrafiltration product water after the cyclic ultrafiltration into the heat exchange component, adjusting the temperature of the ultrafiltration concentrated water, and then introducing the ultrafiltration product water after the temperature adjustment into the purification component for purification treatment, obtaining purified product water and concentrated water after purification, and discharging the purified concentrated water;

[0203] (S03) introducing the purified produced water into the first filter bottle, performing nanofiltration and one-stage reverse osmosis treatment to obtain one-stage concentrated produced water and concentrated water, and discharging the one-stage concentrated produced water into the final produced water tank;

[0204] (S04) introducing the concentrated water from the first stage into the second filter bottle, performing nanofiltration and the first stage and second stage reverse osmosis treatment to obtain the first stage and second stage concentrated water and concentrated water, and discharging the first stage and second stage concentrated water into the final water production tank;

[0205] (S05) introducing the concentrated water from the first stage and second stage into the third filter bottle, performing nanofiltration and first stage and third stage reverse osmosis treatment to obtain the first stage and third stage concentrated water and concentrated water, and discharging the first stage and third stage concentrated water into the final water production tank;

[0206] (S06) The first-stage three-stage concentrated concentrated water is introduced into the first-stage acceleration tube for acceleration treatment, and then the first-stage three-stage concentrated concentrated water after the acceleration treatment is introduced into the fourth filter bottle for secondary reverse osmosis treatment to obtain secondary concentrated water and concentrated water, and the secondary concentrated water is introduced into the final water production tank, and the secondary concentrated concentrated water is discharged into the final concentrated water tank to achieve the recycling of acidic wastewater.

[0207] Taking a certain pigment production plant as an example, the daily amount of acidic wastewater generated is 500t / d, with an acidity of 1.72%. The main components are sulfuric acid and sulfates. The sulfate ion concentration is tested to be 3g / L, the total concentration of heavy metal ions (such as lead, mercury, etc.) is 0.1g / L, and the total concentration of calcium and magnesium ions is 0.08g / L.

[0208] The acidic wastewater treatment data in this example are shown in the following table:

[0209] Table 4

[0210]

[0211] In step (S01), the acidic wastewater is first introduced into the raw water tank, and then the acidic wastewater in the raw water tank is pumped into the first security filter. After filtration, the filtered water is pumped into the ultrafiltration component for ultrafiltration treatment to obtain ultrafiltration product water and concentrated water. The ultrafiltration concentrated water is discharged, and the ultrafiltration product water is introduced back to the raw water tank for 4 cycles of ultrafiltration treatment.

[0212] The magnetic column absorbs magnetic impurities in the wastewater, and the adsorption rate of magnetic impurities can reach more than 95%; the sedimentation barrel uses gravity sedimentation to make large particles settle to the bottom, and the sedimentation efficiency can reach 90%. The filter plate further intercepts fine impurities, and the pH and flow detection ring monitors the water quality in real time. The wastewater that has been initially purified is pumped into the first security filter by the water inlet pump. The PP melt-blown filter element with a precision of 5 microns is used to effectively intercept suspended matter, colloids and other impurities, and the removal rate of suspended matter can reach 98%.

[0213] The ultrafiltration component uses an ultrafiltration membrane made of polyvinylidene fluoride (PVDF) with a molecular weight cutoff of 1000 Daltons. The operating pressure is maintained at 0.13 MPa, and the retention rate of large molecular organic matter can reach more than 85%.

[0214] The ultrafiltration concentrated water is discharged externally, and the ultrafiltration product water flows back to the raw water tank and is recycled for three ultrafiltration treatments. The removal rate of heavy metal ions can reach more than 93%, reducing the heavy metal ion concentration to below 0.035g / L.

[0215] In step (S02), the ultrafiltration water produced after the circulating ultrafiltration is first introduced into the heat exchange component, the temperature of the ultrafiltration concentrated water is increased to 35°C, and then the ultrafiltration water produced after temperature adjustment is introduced into the purification component, and purified using an electric field of 900V / m to obtain purified water and concentrated water, and the purified concentrated water is discharged.

[0216] The heat exchange component uses the principles of heat conduction and convection to raise the water temperature to 35°C, and applies an electric field of 900V / m through the electrode plate to remove high hardness cations through electrodialysis. Under this condition, the removal rate of calcium and magnesium ions can reach more than 97%, reducing the concentration of calcium and magnesium ions to below 0.007g / L.

[0217] In step (S03), the purified product water is first introduced into the first filter bottle, and nanofiltration and one-stage reverse osmosis treatment are performed to obtain one-stage concentrated product water and concentrated water, and the one-stage concentrated product water is discharged into the final product water tank; the molecular weight cutoff of the nanofiltration treatment is 900Da, and the operating pressure is 1.2MPa; the operating pressure of the one-stage reverse osmosis treatment is 2.7MPa.

[0218] The nanofiltration membrane is made of aromatic polyamide, with a molecular weight cutoff of 900Da and an operating pressure of 1.2MPa. The removal rate of divalent ions can reach more than 84%, and the removal rate of organic matter with a molecular weight of 200 to 1000 Daltons can reach 82%. Then the first-stage reverse osmosis treatment is carried out. The reverse osmosis membrane tube is made of composite polyamide and the operating pressure is 2.7MPa to further remove the remaining ions and organic matter.

[0219] In step (S04), the first-stage concentrated concentrated water is first introduced into the second filter bottle for nanofiltration and first-stage two-stage reverse osmosis treatment to obtain first-stage two-stage concentrated water and concentrated water, and the first-stage two-stage concentrated water is discharged into the final water tank; the molecular weight cutoff of the nanofiltration treatment is 900Da, and the operating pressure is 1.4MPa; the operating pressure of the first-stage two-stage reverse osmosis treatment is 2.9MPa.

[0220] The nanofiltration operating pressure is increased to 1.4MPa, and the interception characteristics remain unchanged, and the residual impurities are removed again. Then the first-stage two-stage reverse osmosis treatment is carried out, and the operating pressure is 2.9MPa, and the comprehensive removal rate of the remaining impurities can reach more than 75%.

[0221] In step (S05), the first-stage two-stage concentrated concentrated water is first introduced into the third filter bottle for nanofiltration and first-stage three-stage reverse osmosis treatment to obtain first-stage three-stage concentrated water and concentrated water, and the first-stage three-stage concentrated water is discharged into the final water tank; the molecular weight cutoff of the nanofiltration treatment is 900Da, and the operating pressure is 1.6MPa; the operating pressure of the first-stage three-stage reverse osmosis treatment is 3.2MPa.

[0222] The nanofiltration operating pressure is 1.6MPa, and the reverse osmosis operating pressure is 3.2MPa. After treatment, the removal rate of trace impurities can reach more than 70%.

[0223] In step (S06), the first-stage three-stage concentrated concentrated water is first introduced into the first-stage accelerating tube. Based on the changes in the diameters of the first-stage accelerating tube, the second-stage accelerating tube and the third-stage accelerating tube, a pressure difference is generated in the water flow in the tube, and the water flow rate is increased to 2.2 times the initial flow rate. The accelerated first-stage three-stage concentrated concentrated water is then introduced into the fourth filter bottle for secondary reverse osmosis treatment; the operating pressure of the secondary reverse osmosis treatment is 4.5MPa.

[0224] The initial velocity of the fluid increases rapidly from 20m / s to 42m / s. Under high-speed water flow, the removal rate of extremely trace impurities can reach more than 65%.

[0225] The present invention has been described in detail above by general description and specific embodiments, but it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, these modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. The full membrane treatment process for purifying and concentrating the acid in the acidic wastewater is characterized by: Includes the following step, (S01) introducing acidic wastewater into a raw water tank, and then pumping the acidic wastewater into a first security filter, and after filtration, pumping the filtered water into an ultrafiltration component for ultrafiltration treatment, and obtaining ultrafiltration product water and concentrated water after ultrafiltration, discharging the ultrafiltration concentrated water, and introducing the ultrafiltration product water back into the raw water tank for cyclic ultrafiltration; The ultrafiltration component (300) comprises a membrane shell (301), the membrane shell (301) is arranged on one side of the first security filter (200), a fixing frame (303) is arranged on the inner side of the membrane shell (301), a plurality of ultrafiltration pipes (304) are arranged on the inner side of the fixing frame (303), a transmission column (305) is fixedly arranged at the center of the fixing frame (303), a driving motor (306) is arranged at the bottom end of the driving column (305), and the output end of the driving motor (306) is fixedly connected to the driving column (305); (S02) introducing the ultrafiltration product water after the cyclic ultrafiltration into the heat exchange component, adjusting the temperature of the ultrafiltration concentrated water, and then introducing the ultrafiltration product water after the temperature adjustment into the purification component for purification treatment, obtaining purified product water and concentrated water after purification, and discharging the purified concentrated water; The heat exchange component (400) comprises a heat insulation shell (402), wherein the heat insulation shell (402) is fixedly connected to the main frame (100), a first heat exchange row (401) is arranged on one side of the heat insulation shell (402), a second heat exchange row (404) is arranged on the side of the heat insulation shell (402) away from the first heat exchange row (401), a twelfth flow guide pipe (4041) is arranged on the side of the second heat exchange row (404) away from the heat insulation shell (402), a ball valve (405) is arranged on the side of the twelfth flow guide pipe (4041) away from the second heat exchange row (404), a thirteenth flow guide pipe (4051) is arranged on one end of the ball valve (405) away from the twelfth flow guide pipe (4041), and the thirteenth flow guide pipe (4051) is connected to the purification component (500); The purification component (500) comprises an insulating shell (501), the insulating shell (501) is fixedly connected to the main frame (100), an electrode plate (502) is arranged on the side of the insulating shell (501), a liquid level ball rod (503) is slidably connected to the top of the insulating shell (501), a liquid level display (5031) is arranged on the top of the liquid level ball rod (503), and an insulating tube (504) is arranged on one side of the insulating shell (501); (S03) introducing the purified produced water into the first filter bottle, performing nanofiltration and one-stage reverse osmosis treatment to obtain one-stage concentrated produced water and concentrated water, and discharging the one-stage concentrated produced water into the final produced water tank; (S04) introducing the concentrated water from the first stage into the second filter bottle, performing nanofiltration and the first stage and second stage reverse osmosis treatment to obtain the first stage and second stage concentrated water and concentrated water, and discharging the first stage and second stage concentrated water into the final water production tank; (S05) introducing the concentrated water from the first stage and second stage into the third filter bottle, performing nanofiltration and first stage and third stage reverse osmosis treatment to obtain the first stage and third stage concentrated water and concentrated water, and discharging the first stage and third stage concentrated water into the final water production tank; (S06) introducing the first-stage three-stage concentrated concentrated water into the first-stage acceleration tube for acceleration treatment, and then introducing the first-stage three-stage concentrated concentrated water after the acceleration treatment into the fourth filter bottle for secondary reverse osmosis treatment to obtain secondary concentrated water and concentrated water, introducing the secondary concentrated water into the final water tank, and discharging the secondary concentrated concentrated water into the final concentrated water tank to achieve the recycling of acidic wastewater; A device for purifying and concentrating acid in acidic wastewater by a full membrane treatment process comprises a main frame (100), a raw water tank (101) is arranged on one side above the main frame (100), a first security filter (200) is arranged on one side of the raw water tank (101), an ultrafiltration component (300) is arranged on the side of the first security filter (200) away from the raw water tank (101), and a heat exchange component is arranged below the side of the ultrafiltration component (300) away from the first security filter (200). (400), a purification component (500) is arranged on a side of the heat exchange component (400) close to the ultrafiltration component (300), a nanofiltration reverse osmosis component (600) is arranged on a side of the purification component (500) away from the heat exchange component (400), an acceleration component (700) is arranged on a side of the nanofiltration reverse osmosis component (600) away from the purification component (500), and a separation component (800) is arranged on a side of the acceleration component (700) away from the nanofiltration reverse osmosis component (600).

2. The full membrane treatment process for purifying and concentrating acid in acidic wastewater according to claim 1 is characterized by: In the step (S01), the acidic wastewater is first introduced into the raw water tank, and then the acidic wastewater in the raw water tank is pumped into the first security filter. After filtration, the filtered water is pumped into the ultrafiltration component for ultrafiltration treatment to obtain ultrafiltration product water and concentrated water. The ultrafiltration concentrated water is discharged and the ultrafiltration product water is introduced back to the raw water tank for 2 to 5 cycles of ultrafiltration treatment.

3. The full membrane treatment process for purifying and concentrating acid in acidic wastewater according to claim 1 is characterized by: In the step (S02), the ultrafiltration product water after the circulating ultrafiltration is first introduced into the heat exchange component, the temperature of the ultrafiltration concentrated water is increased to 25-40°C, and then the ultrafiltration product water after temperature adjustment is introduced into the purification component, and purified using an electric field of 500-1000V / m to obtain purified product water and concentrated water, and the purified concentrated water is discharged.

4. The full membrane treatment process for purifying and concentrating acid in acidic wastewater according to claim 1 is characterized by: In the step (S03), the purified product water is first introduced into the first filter bottle, and nanofiltration and one-stage reverse osmosis treatment are performed to obtain one-stage concentrated product water and concentrated water, and the one-stage concentrated product water is discharged into the final product water tank; the molecular weight cutoff of the nanofiltration treatment is 200-1000Da, and the operating pressure is 0.5-1.5MPa; the operating pressure of the one-stage reverse osmosis treatment is 1.5-3.0MPa.

5. The full membrane treatment process for purifying and concentrating acid in acidic wastewater according to claim 1 is characterized by: In the step (S04), the first-stage concentrated concentrated water is first introduced into the second filter bottle, and nanofiltration and first-stage two-stage reverse osmosis treatment are performed to obtain first-stage two-stage concentrated water and concentrated water, and the first-stage two-stage concentrated water is discharged into the final water production tank; the molecular weight cutoff of the nanofiltration treatment is 200 to 1000Da, and the operating pressure is 0.6 to 1.6MPa; the operating pressure of the first-stage two-stage reverse osmosis treatment is 1.8 to 3.2MPa.

6. The full membrane treatment process for purifying and concentrating acid in acidic wastewater according to claim 1 is characterized by: In the step (S05), the concentrated water from the first stage and second stage is first introduced into the third filter bottle, and nanofiltration and first stage and third stage reverse osmosis treatment are performed to obtain first stage and third stage concentrated water product and concentrated water, and the first stage and third stage concentrated water product is discharged into the final water product tank; the molecular weight cutoff of the nanofiltration treatment is 200 to 1000Da, and the operating pressure is 0.7 to 1.7MPa; the operating pressure of the first stage and third stage reverse osmosis treatment is 2.0 to 3.5MPa.

7. The full membrane treatment process for purifying and concentrating acid in acidic wastewater according to claim 1 is characterized by: In the step (S06), the first-stage three-stage concentrated concentrated water is first introduced into the first-stage accelerating tube. Based on the changes in the diameters of the first-stage accelerating tube, the second-stage accelerating tube and the third-stage accelerating tube, a pressure difference is generated in the water flow in the tube, and the water flow rate is increased to 1.5 to 2.5 times the initial flow rate. The accelerated first-stage three-stage concentrated concentrated water is then introduced into the fourth filter bottle for secondary reverse osmosis treatment; the operating pressure of the secondary reverse osmosis treatment is 3.0 to 5.0 MPa.

8. The full membrane treatment process for purifying and concentrating acid in acidic wastewater according to claim 1 is characterized by: A water inlet pipe (1011) is provided on one side of the raw water tank (101); a first flow guide pipe (1012) is provided on a side of the raw water tank (101) away from the water inlet pipe (1011); a water inlet pump (1013) is provided on one end of the first flow guide pipe (1012) away from the raw water tank (101); a second flow guide pipe (1014) is provided on one side of the water inlet pump (1013) away from the first flow guide pipe (1012); and one end of the second flow guide pipe (1014) away from the water inlet pump (1013) is connected to a first safety filter (200); The raw water tank (101) comprises a spiral tube (1015), wherein the spiral tube (1015) is arranged at the top of the raw water tank (101), a magnetic column (1016) is arranged on the inner side of the spiral tube (1015), a sedimentation barrel (1017) is arranged at the bottom end of the spiral tube (1015), a filter plate (1018) is arranged at the bottom end of the sedimentation barrel (1017), and a pH and flow detection ring (1019) is arranged on the outer side of the filter plate (1018).

9. The full membrane treatment process for purifying and concentrating acid in acidic wastewater according to claim 1, characterized in that: The nanofiltration reverse osmosis assembly (600) comprises a first filter bottle (601), the first filter bottle (601) being arranged on one side of an insulating tube (504), a first branch pipe (5041) being arranged on the side of the insulating tube (504) close to the first filter bottle (601), an end of the first branch pipe (5041) away from the insulating tube (504) being connected to the first filter bottle (601), a fourteenth flow guide pipe (6011) being arranged on the top of the first filter bottle (601), a second filter bottle (602) being arranged on the end of the fourteenth flow guide pipe (6011) away from the first filter bottle (601), and a second filter bottle (602) being arranged on the side of the insulating tube (504) close to the second filter bottle (602). A second branch pipe (5042) is provided on one side, and an end of the second branch pipe (5042) away from the insulating tube (504) is connected to the second filter bottle (602), a fifteenth flow guide pipe (6021) is provided at the top of the second filter bottle (602), a third filter bottle (603) is provided at an end of the fifteenth flow guide pipe (6021) away from the second filter bottle (602), an end of the insulating tube (504) away from the insulating shell (501) is connected to the third filter bottle (603), a sixteenth flow guide pipe (6031) is provided at the top of the third filter bottle (603), and the sixteenth flow guide pipe (6031) is connected to the acceleration component (700); A nanofiltration membrane (6012) is arranged on the top of the first filter bottle (601), a plurality of liquid conduits (6013) are arranged below the nanofiltration membrane (6012), a first reverse osmosis barrel (6014) is arranged at the bottom end of the liquid conduit (6013), a plurality of reverse osmosis membrane tubes (60141) are arranged on the inner side of the first reverse osmosis barrel (6014), and a second reverse osmosis barrel (6015) is arranged below the first reverse osmosis barrel (6014).

10. The full membrane treatment process for purifying and concentrating acid in acidic wastewater according to claim 1, characterized in that: The accelerating assembly (700) comprises an accelerating bracket (701), the accelerating bracket (701) being arranged on a main frame (100), a primary accelerating tube (702) being arranged inside the accelerating bracket (701), a secondary accelerating tube (703) being arranged at one end of the primary accelerating tube (702), a tertiary accelerating tube (704) being arranged at one end of the secondary accelerating tube (703) away from the primary accelerating tube (702), and a separation assembly (800) being arranged at one end of the tertiary accelerating tube (704) away from the secondary accelerating tube (703). The invention comprises a fourth filter bottle (801), wherein the fourth filter bottle (801) is fixedly connected to the main frame (100), a first separation tube (8011) is arranged on one side of the top of the fourth filter bottle (801), and an end of the first separation tube (8011) away from the fourth filter bottle (801) is connected to a final concentrated water tank (103), and a second separation tube (8012) is arranged on one side of the bottom of the fourth filter bottle (801), and an end of the second separation tube (8012) away from the fourth filter bottle (801) is connected to a final produced water tank (104).

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