63 results about "Transmembrane pressure" patented technology

The invention relates to the technical field of data processing, and discloses an automatic control method and system for wastewater desalination treatment based on the Internet of Things. The method comprises the following steps: acquiring a membrane surface image, an interface potential, an infrared spectrum, a transmembrane pressure difference, a feeding flow rate and a flocculation image; calculating a salt gradient attention feature vector according to the salt concentration difference value and the Beckey number; inputting the multi-modal data into a membrane pollution time sequence memory network to obtain a pollution development rate and a flocculant adding proportion; extracting a floc particle size parameter to obtain a flocculation effect score; and constructing a multi-objective function optimization solution to obtain a control instruction. The salt gradient attention mechanism and the membrane pollution time sequence memory network are introduced, and visual image recognition and multi-modal data fusion are combined, so that the problems of inaccurate membrane pollution state evaluation, low intelligent level of a control algorithm and insufficient multi-target collaborative optimization capability in the prior art are solved; the automation level and the treatment efficiency of wastewater desalination treatment are improved.

The application relates to the technical field of data processing, and discloses a wastewater desalination treatment automatic control method and system based on an Internet of Things. The method comprises the following steps: collecting a membrane surface image, an interfacial potential, an infrared spectrum, a transmembrane pressure difference, a feed flow and a flocculation image; calculating a salt gradient attention feature vector according to a salt concentration difference value and a Berkeley number; inputting the membrane pollution time sequence memory network combined with multi-modal data to obtain a pollution development rate and a flocculant dosage ratio; extracting a floc particle size parameter to obtain a flocculation effect score; and constructing a multi-objective function optimization solution to obtain a control instruction. By introducing a salt gradient attention mechanism and a membrane pollution time sequence memory network, combining visual image recognition and multi-modal data fusion, the problems of inaccurate membrane pollution state evaluation, low intelligent level of a control algorithm and insufficient multi-target collaborative optimization capability in the prior art are solved, and the automation level and processing efficiency of wastewater desalination treatment are improved.

A control device (10) and method for determining the permeability state of a forward osmosis (FO) membrane (2c) of a FO device (2) in a dialysate generator (1). The FO membrane (2c) separates a feed side (2a) and a draw side (2b) of the FO device (2). The FO device (2) has a feed inlet port (E) in fluid communication with the feed side (2a). in ) and the feed outlet port (E out ) and a draw inlet port (L ) in fluid communication with the draw side (2b). in ) and draw outlet port (L out ). The method includes providing (S1) a flow of pure water to the feed side (2a) and providing (S2) a flow of pure water to the draw side (2b). The method further includes monitoring (s3) one or more pressures indicative of a transmembrane pressure, TMP, between the feed side (2a) and the draw side (2b). The method further includes stopping (S4) the flow through one of the ports such that the TMP is maintained constant and of a non-zero magnitude, controlling (S5) the flow to or from one of the feed side (2a) and the draw side (2b) with the flow stopped based on the monitored one or more pressures, and determining (S7) a permeability state of the FO membrane based on a characteristic indicative of the flow.

The present application relates to the technical field of blood monitoring, in particular to a vascular health assessment and intelligent nursing system for hemodialysis patients. The degree of venous reflux obstruction is determined based on the change trend and degree of venous pressure data within each dialysis period, and the degree of inconsistency between the change trends of venous pressure data and transmembrane pressure data. The degree of arterial supply obstruction is determined based on the change trend and degree of arterial pressure data within each dialysis period. The suspected internal fistula obstruction period is determined based on the change trend of the degree of venous reflux obstruction and the degree of arterial supply obstruction. The nursing intervention prompting degree of the patient to be tested is determined based on the relationship between the blood flow data and arterial pressure data of each dialysis stage of the patient to be tested within the suspected internal fistula obstruction period, and the blood flow data of the non-dialysis stage. The internal fistula nursing scheme is determined. The present application realizes early warning of internal fistula dysfunction based on the change of venous and arterial pressure of the blood circulation loop during dialysis.

The invention relates to the technical field of sewage treatment, and particularly discloses a sewage treatment control method based on AI intelligent driving, and the method comprises the following steps: S1, collecting parameters in real time; s2, inputting the parameters into a pre-trained random forest model to obtain an output aeration rate set value, a sludge reflux ratio and a carbon source feeding rate; s3, adjusting the rotating speed of an aeration fan of the aerobic tank according to an aeration rate set value, adjusting the frequency of a sludge reflux pump according to a sludge reflux ratio, and adjusting a metering pump to add a sodium acetate solution according to a carbon source adding rate; and S4, when the turbidity of the MBR membrane pool exceeds a turbidity threshold value, giving out an early warning, further judging whether the transmembrane pressure difference of the MBR membrane pool exceeds a transmembrane pressure difference threshold value or whether the membrane flux attenuation exceeds a membrane flux attenuation threshold value, and if so, starting a pulse backwashing program.

The application provides a non-immersed transmembrane pressure detection system, which is characterized in that: a liquid inlet detection module, a permeation end detection module, a backflow end detection module and a transmembrane pressure calculation module are arranged, a non-immersed transmembrane pressure detection circuit is arranged in each of the liquid inlet detection module, the permeation end detection module and the backflow end detection module, the corresponding transmembrane pressure calculation result is obtained by calculating the liquid inlet detection signal, the permeation end detection signal and the backflow end detection signal output by the circuit, a four-stage amplification and analog signal isolation circuit composed of a high-precision resistance voltage division network, a first-stage operational amplifier circuit, a second-stage operational amplifier circuit, a linear optical coupler, a third-stage operational amplifier circuit and a fourth-stage operational amplifier circuit is arranged in the non-immersed transmembrane pressure detection circuit, the detected current signal is converted into an electrical signal by using the operational amplification piezoelectric effect, and the piezoelectric type can provide an anti-interference signal electrical output after isolation chip. The application has good linearity, simple circuit calculation and effectively solves the problem of electrical signal isolation between an analog signal and a single-chip microcomputer application system.

The utility model provides an ultrafiltration membrane pressure detection device, which relates to the technical field of ultrafiltration membrane pressure detection, and comprises a shell, the top of the shell is provided with a top cover, the top of the top cover is connected with a drain outlet, the front surface of the shell is connected with a monitoring alarm assembly, and the monitoring alarm assembly comprises a purified water outlet. According to the utility model, the pressure sensor and the flow sensor are respectively arranged at the purified water outlet and the drain outlet, so that a real-time monitoring effect can be achieved, and when the flow or the pressure difference reaches a set numerical value, the PLC controller gives an instruction to carry out systematic backwashing, forward flushing and other maintenance actions on the membrane at the moment; and if the trans-membrane pressure difference almost does not exist, the serious problems such as membrane breakage are possibly caused, and the alarm can automatically give an alarm to remind an operator to check the fault of the membrane in time, so that the problem that the membrane cannot be normally used due to blockage is avoided.

The invention relates to the technical field of sodium chondroitin sulfate, in particular to sodium chondroitin sulfate with a high cartilage repair effect and a preparation method thereof.The sodium chondroitin sulfate initial feed liquid is provided, the pH value of the sodium chondroitin sulfate initial feed liquid is adjusted to a preset acidic pH value, and at the preset reaction temperature, the pH value and the reaction temperature are maintained for reaction time, so that the chondroitin sulfate with the high cartilage repair effect is obtained. The method comprises the following steps: adding a sulfated disaccharide unit CS-0 into a feed liquid to precipitate out a non-sulfated disaccharide unit CS-0 in the feed liquid, carrying out solid-liquid separation on the feed liquid, and removing the CS-0 precipitate to obtain a supernatant; pumping the supernatant into a gradient membrane separation system under controlled transmembrane pressure difference and feed liquid temperature, and separating the supernatant into three component flows with different molecular weight intervals; the concentration of the three component flows is monitored, the volume flow of each component flow is dynamically adjusted according to the preset molecular weight and mass distribution proportion, the chondroitin sulfate sodium product with the fixed molecular weight distribution is obtained, and the biological activity and the application value of the chondroitin sulfate sodium are improved.

This application relates to the field of wastewater treatment technology, specifically to a method for controlling the reuse of recycled water in wastewater treatment processes. The method includes: collecting various parameter data; calculating the transmembrane pressure difference based on pressure, fitting a straight line to obtain the rate of change of the transmembrane pressure difference; constructing a trend sequence using desalination rate, transmembrane pressure difference, and permeate flow rate, and determining the RO membrane quality coefficient based on the variance of the trend sequence, the correlation differences among the data constituting the trend sequence, and the rate of change of the transmembrane pressure difference; fitting the permeate flow rate curve, and determining the pre-RO membrane characteristic coefficient based on the difference in the permeate flow rate change rate, the mean of influent turbidity, the mean of elemental change rate, and the RO membrane quality coefficient; adjusting the membrane cleaning interval after the adjustment in the previous cycle based on the RO membrane quality coefficient and the pre-RO membrane characteristic coefficient to obtain the adjusted membrane cleaning interval for each cycle; and cleaning the RO membrane based on the adjusted membrane cleaning interval for each cycle. This application ensures the stability of water treatment quality.

The invention relates to the technical field of sewage treatment, and particularly discloses a mountainous area sewage treatment method which comprises the following steps: S1, collecting inlet water quality data, environmental data and process operation parameters of a mountainous area sewage treatment station in real time through a sensor network; s2, inputting the data acquired in the step S1 into an AI optimization control module, and outputting real-time optimization control parameters; s3, adjusting the operating frequency of an aeration fan and the rotating speed of a sludge reflux pump according to the optimized control parameters obtained in the step S2; s4, monitoring the transmembrane pressure TMP and the membrane pollution index MFI of the MBR membrane component in real time, and starting an online chemical cleaning program when the TMP exceeds a threshold value; and S5, integrating the operation data of each distributed sewage treatment station through a cloud platform monitoring system, and realizing regional collaborative optimization and fault early warning by adopting an adaptive model predictive control (AMPC) strategy.

This invention discloses a membrane bioreactor (MBR) treatment method and a field return system for wastewater from sheep slaughterhouses. After three-stage pretreatment, the wastewater undergoes two-stage anoxic-aerobic denitrification, with segmented influent and two-stage internal recirculation. A short-range nitrification window is created in the first-stage aerobic zone with low dissolved oxygen through intermittent aeration, while stable nitrification occurs in the second-stage aerobic zone. The biochemically treated effluent enters a PVDF submerged ultrafiltration (MBR), where the mixed liquor suspended solids concentration and flux are controlled. Backwashing / relaxation and chemical cleaning sequences are triggered by the increase in transmembrane pressure difference per unit time, enhancing shock and fouling resistance. MBR permeate is fed into a field return tank and connected to the field return system. Precise water and fertilizer return and salt control are achieved through rapid nitrogen and phosphorus measurement, application decision-making, and stratified drip irrigation valve control. This scheme can achieve effluent ammonia nitrogen ≤3 mg / L, high total nitrogen removal, and reduced membrane fouling and nitrogen loss.

This invention discloses a dual-inspection device and method for single membranes in a water treatment membrane module, relating to the field of water treatment technology. Each single membrane is equipped with an outlet solenoid valve. The main control box controls the opening and closing of the outlet solenoid valve to perform individual inspections and a binary inspection of the membrane module. The main control box identifies damaged single membranes based on the outlet turbidity value measured by a turbidity detector; it also identifies fouled single membranes based on the transmembrane pressure difference value measured by a pressure sensor, cleans the fouled single membranes, while normal membranes continue to produce water. Through individual inspection and binary inspection methods, as well as targeted membrane fouling cleaning, rapid inspection of membrane integrity and filtration performance can be achieved, and damaged and fouled membranes can be located. Then, corresponding measures such as targeted membrane fouling control can be taken, avoiding the occurrence of downtime for the entire membrane module due to problems with individual membranes. This greatly improves the water treatment efficiency of the membrane module and significantly reduces the energy consumption of the equipment.

The disclosure relates to an extracorporeal blood treatment machine comprising a dialyzer (19) having hollow fibers (2) and a blood side (4) and a dialyzing fluid side (6), an extracorporeal blood circuit, and a dialyzing fluid circuit. The extracorporeal blood treatment machine has a control unit (48) which is configured and prepared to perform automatic priming of the blood treatment machine such that it sets a transmembrane pressure (10) with a pressure gradient from the dialyzing fluid side (6) to the blood side (4) and / or from the blood side (4) to the dialyzing fluid side (6) in order to remove air from the semipermeable membrane (8) during priming. The disclosure further relates to a method for priming a dialyzer (19) having hollow fibers (2) and to a computer program.

This invention relates to the field of ethylene glycol preparation, specifically to a method for the direct production of ethylene glycol from ethylene. The method includes: reacting ethylene with hydrogen peroxide in the presence of an oxidative hydration bifunctional catalyst to obtain a material containing ethylene glycol, and collecting the product after separation via a metal-ceramic composite membrane. Using this method, ethylene glycol can be produced in a one-step process. The reaction exhibits high hydrogen peroxide utilization, ethylene conversion rate, and ethylene glycol selectivity, along with high catalyst activity and stability. During separation, the transmembrane pressure difference is small, allowing the separation system to operate continuously for extended periods. The resulting product liquid has a low catalyst concentration.

This invention relates to the field of water treatment equipment condition monitoring technology, and in particular to a full life-cycle operation and maintenance system for membrane separation water treatment equipment. The system acquires influent environmental data to generate scene labels and configures tolerance coefficients. A baseline array is constructed based on the scene labels and the initial transmembrane pressure difference. Real-time operating data is matched to determine the target scene label. The difference between the real-time pressure difference and the initial pressure difference is calculated to output deviation characteristics. When a threshold is exceeded, a cleaning command is issued, and an attenuation index is calculated based on the pressure difference after cleaning to update the baseline array. The permeate flux within adjacent cleaning intervals is accumulated to generate a periodic load. The attenuation index is normalized using the periodic load and tolerance coefficient to output the aging equivalent. Each aging equivalent is accumulated over time to generate a cumulative attenuation value. When the cumulative attenuation value exceeds a preset critical value, an equipment replacement command is triggered. This improves the long-term accuracy of membrane module condition monitoring and effectively prevents equipment from exceeding its service life.

This invention discloses a hollow fiber column transmembrane pressure control system, comprising: a hollow fiber column having an inlet end, an outlet end, and a filter end; a first delivery pump connected to the inlet end of the hollow fiber column; a second delivery pump connected to the outlet end of the hollow fiber column; an ultrasonic flow meter connected to the filter end of the hollow fiber column; and a pressure monitoring unit for monitoring the pressure at the inlet end, outlet end, and filter end of the hollow fiber column. This invention addresses the need for dynamic adjustment of transmembrane pressure due to changes in membrane flux throughout the entire service life of the hollow fiber column, overcoming the shortcomings of existing solutions.

The application discloses a printing and dyeing wastewater zero discharge treatment process based on low-pressure high-multiple membrane concentration and salt separation cooperation. The wastewater sequentially passes through double-alkali softening pretreatment, organic pollutant treatment, forward osmosis low-pressure high-multiple concentration treatment, salt separation treatment and evaporation crystallization steps; wherein the forward osmosis low-pressure high-multiple concentration treatment is operated in sections along the flow direction, the osmotic pressure difference is gradually increased, the transmembrane pressure difference is gradually decreased, and the interface electrochemical buffer and low-frequency gas-liquid disturbance can be set to inhibit the concentration polarization and pollution. The concentrated liquid is separated into two salt water streams mainly containing Na2SO4 and NaCl through nanofiltration, and is evaporated and crystallized respectively; and the water produced by the draw solution is returned and reused. The process realizes high-multiple concentration and stable salt separation under low mechanical pressure, reduces energy consumption, improves water recovery rate and crystal purity, and realizes wastewater zero discharge.

The utility model provides a tubular microfiltration membrane and a reaction tank. According to the micro-filtration membrane, the spiral guide sheets are arranged in the membrane tube main body to guide the tubular bundling separation membrane to spirally extend, so that a rotational flow effect is formed to break through a traditional straight-through flow channel mode, the turbulence degree of fluid is enhanced, and concentration polarization is reduced. The split type design is adopted in the structure, an upper shell and a lower shell are welded and formed, end covers at the two ends are assembled with connecting grooves through clamping blocks, a rubber plate with holes fixes a film bundle through holes, clamping grooves in the edges of the rubber plate are embedded into grooves of guide pieces to prevent flow channel bias flow, and an additionally-arranged axial flow disturbing rod and a spiral flow channel cooperate to generate multi-stage eddy currents to strengthen boundary layer disturbance. The composite supporting structure is composed of a stainless steel wire net and a gradient pore ceramic frame, the outer net improves the mechanical strength, the inner layer ceramic frame adopts 35-60% radial gradient pore distribution to achieve progressive throttling, the transmembrane pressure difference is optimized, and membrane wires are protected.

The application provides a hollow fiber membrane cleaning pressure self-adaptive adjustment control method and system, relates to the technical field of control, and comprises the following steps: determining a target transmembrane pressure difference interval by flushing an inlet water side and a water production side in a set temperature range; according to a transmembrane pressure difference deviation and a change rate, the inlet water pump rotating speed and the concentrated water discharge valve opening degree are cooperatively regulated in sequence of valve first and pump second; when the transmembrane pressure difference reaches the upper limit and the pollution is reversible, an impact cleaning sequence is generated, the concentrated water valve opening degree is increased, and the inlet water pump rotating speed is increased to form shearing scouring. The application realizes self-adaptive adjustment of the cleaning pressure in the membrane pollution process, and improves the membrane cleaning efficiency.

This invention belongs to the field of wastewater treatment and resource utilization technology, and particularly relates to a system and method for low-energy anaerobic-gravity membrane wastewater resource utilization treatment. The system includes: a pretreatment unit, an anaerobic biofilm tank unit, a gas-liquid separation and flow stabilization unit, a gravity-driven membrane bioreactor unit, and a permeate reuse unit, all connected in series. The anaerobic biofilm tank unit is also connected to a biogas collection unit and a sludge treatment unit. After pretreatment, wastewater enters the anaerobic biofilm tank, where anaerobic microorganisms degrade organic pollutants and produce biogas. The anaerobic effluent, after gas-liquid separation and flow stabilization, enters the gravity-driven membrane bioreactor unit. Low-energy membrane separation is achieved by relying on the natural transmembrane pressure difference formed by the liquid level difference. The permeate is disinfected and reused, while the biogas and residual sludge are utilized for resource recovery. This invention eliminates the need for high-energy-consuming suction pumps and aeration systems, reducing operating energy consumption, and enables the resource utilization of biogas and residual sludge.

This invention discloses a water treatment method that enhances the coupling of ozone catalytic surface functionalization, belonging to the field of water treatment technology. The method first prepares a three-layer γ-Al₂O₃ ceramic membrane, and then in situ loads δ-MnO₂ nanosheets onto the membrane surface to form a catalytically functionalized ceramic membrane. After pretreatment, wastewater enters the membrane module in a cross-flow manner, simultaneously activating ultrasonic and ozone aeration to achieve deep coupling of ultrasonic enhancement, ozone catalytic oxidation, and membrane separation. Intelligent feedback regulation is achieved through online monitoring of transmembrane pressure difference and effluent COD, and in-situ online cleaning and chemical regeneration are used to maintain membrane flux. This integrates membrane separation, catalytic oxidation, ultrasonic self-cleaning, and intelligent control, significantly improving the removal efficiency of recalcitrant organic matter, inhibiting membrane fouling at its source, and ensuring stable system operation and easy maintenance. It is suitable for treating high-concentration recalcitrant organic wastewater from dyeing, pharmaceutical, and chemical industries, with effluent meeting the Class A discharge standard for urban wastewater treatment plants.

The invention discloses a soybean phospholipid deoiling method based on membrane separation. Aiming at the problems that a high-viscosity phospholipid feed liquid easily causes membrane pollution and is fast in flux attenuation, the invention provides a membrane separation method combining a spiral flow channel configuration and an axial oscillation flow field, and the membrane separation method comprises the following steps: dissolving crude soybean phospholipid in a non-polar solvent, and centrifuging to remove insoluble substances to obtain a raw material liquid; pumping the raw material solution into a spiral sleeve type hollow fiber membrane separation device, applying axial oscillation, separating at a specific flow rate, transmembrane pressure difference, temperature and oscillation frequency, and collecting trapped fluid; and carrying out reduced pressure distillation and vacuum drying to obtain a deoiled soybean phospholipid finished product. By utilizing the characteristic that the phospholipid forms reverse micelles in a non-polar solvent, secondary flow induced by a spiral flow channel is cooperated with an oscillating flow field, membrane pollution is remarkably inhibited, the phospholipid recovery rate exceeds 95%, the total phospholipid content of a finished product is higher than 96.5%, the solvent can be recycled, and the method is suitable for continuous industrial production.

The invention relates to the field of data prediction, in particular to a transmembrane pressure prediction method and device, equipment and a medium, and the method comprises the steps: obtaining historical transmembrane pressures, historical dialyzer pressure differences and historical dialysis hydraulic pressures corresponding to a plurality of first historical periods before a prediction period; determining the first stability of the dialyzer pressure difference according to the historical dialyzer pressure differences corresponding to the multiple first historical periods; determining second stability of the dialysis hydraulic pressure according to the historical dialysis hydraulic pressures corresponding to the multiple first historical periods; determining a transmembrane pressure prediction model according to the first stability and the second stability; and determining the transmembrane pressure of the prediction period through the transmembrane pressure prediction model according to the historical transmembrane pressure corresponding to each of the plurality of first historical periods, so that the future transmembrane pressure trend can be predicted.

The present application relates to the technical field of fermentation engineering and microbial culture medium matrix regulation, and discloses a compound culture medium for fermenting fish-source specific bacteria and a preparation method thereof, which comprises the following steps: adding sodium citrate to reduce the dynamic viscosity of fish-source initial materials, then hydrolyzing by using acid endoprotease, cross-flow filtering by using an ultrafiltration membrane assembly, and determining the transmembrane pressure difference to exclude the interference of polarization layer and determine the hydrolysis end point; hydrolyzing the ultrafiltration permeate under closed low-oxygen conditions by using neutral exopeptidase; and adding potassium dihydrogen phosphate and magnesium sulfate quantitatively to construct a steady-state coordination solvation structure. The present application blocks the excessive cleavage of polypeptides into free amino acids, limits the accumulation amount of free amino acids below the inhibition threshold, and eliminates the metabolic inhibition and fermentation amplification lag of specific bacteria in the downstream fermentation system of microorganisms.

This invention relates to a self-optimization method for acetylene purification operating parameters based on the coupling of membrane permeation characteristics and operating conditions, belonging to the field of gas separation technology. The method includes: obtaining the functional relationship between the permeability coefficient of a single-component gas and pressure and temperature; establishing a response model of impurity removal rate and acetylene loss rate with transmembrane pressure difference and feed flow rate, introducing correction terms for adsorption saturation and diffusion mechanisms; defining a multi-objective function and constraints including product purity, impurity reduction, acetylene loss rate, and energy consumption; using an iterative optimization algorithm to obtain the optimal operating parameters; distributing the optimal parameters to the control system, and periodically correcting the model parameters based on online analysis feedback. This invention also integrates operational limit assessment and membrane performance degradation diagnosis functions. This invention transforms the actual permeation characteristics of membrane materials into executable operating parameters, reducing acetylene loss and energy consumption while ensuring high-purity acetylene, providing a quantitative design basis for the engineering scale-up of acetylene membrane separation and purification.

The invention discloses an energy recovery process based on a pressure membrane technology, which specifically comprises the following steps: S1, system initialization treatment, S2, membrane separation and energy recovery treatment, S3, transmembrane pressure difference dynamic regulation and control treatment, S4, membrane cleaning and regeneration treatment, and S5, system shutdown treatment, and relates to the technical field of membrane separation. According to the energy recovery process based on the pressure membrane technology, direct conversion of the pressure energy of the high-pressure concentrated solution to the high pressure of the whole system is achieved through a compressed air medium, the energy recovery efficiency can reach 75%-85% and is improved by 15%-20% compared with a traditional turbine power generation type recovery device, the comprehensive energy consumption of the system is reduced by 30%-40%, and the operation stability is good; dynamic regulation and control of transmembrane pressure difference are realized by adopting a PLC system, the pressure fluctuation amplitude is controlled within + / -3%, the retention rate stability of a membrane assembly is improved by 5-8%, the product quality consistency is remarkably improved, the service life of equipment is prolonged, the membrane assembly and a pump set are prevented from being directly impacted by high-pressure fluid through a gas-liquid buffer structure, and the service life of the membrane assembly is prolonged by more than 30%.

The invention discloses a surface-modified low-pass hemodialysis membrane as well as a preparation method and application thereof, and belongs to the technical field of hemodialysis membranes. The dialysis membrane comprises a base membrane and a modified coating located on the inner surface of the base membrane. The base membrane is a polyether sulfone hollow fiber membrane; the modified coating is of a two-dimensional net structure formed by an aminobenzene substance and an aldehyde substance containing a sulfonic acid group through a polymerization reaction, and the average pore diameter of the structure is 1.5-1.8 nm. Furthermore, the invention also provides a preparation method of the surface-modified low-pass hemodialysis membrane and application of the surface-modified low-pass hemodialysis membrane in a hemodialyzer. The hemodialysis membrane provided by the invention has the advantages that the hemodialysis membrane has a low ultrafiltration coefficient, so that the hemodialysis membrane still keeps relatively high toxin removal efficiency on the premise of low transmembrane and low ultrafiltration coefficient, and has relatively good biocompatibility.