26 results about "Membrane distillation" patented technology

The application provides a polytetrafluoroethylene / polyamide subcomposite fiber membrane and a preparation method and application thereof. The preparation method of the polytetrafluoroethylene / polyamide subcomposite fiber membrane comprises the following steps: providing a spinning solution and performing electrostatic spinning, performing heat treatment after obtaining a fiber membrane, and finally obtaining a polytetrafluoroethylene / polyamide subcomposite fiber membrane; the spinning solution comprises a spinning aid, polytetrafluoroethylene and a polyamide acid salt; the spinning aid is selected from one or more of polyethylene oxide, polyvinylpyrrolidone and polyvinyl alcohol. The composite fiber membrane prepared by the technical scheme has good hydrophobicity and good wet resistance, and has uniform and stable pore structure, good pore connectivity and good air permeability of the membrane, and is very suitable for being used in the fields of membrane distillation and the like.

The application belongs to the technical field of membrane distillation, and discloses a kind of persistent super-hydrophobic uniform pore separation membrane and its preparation method and application, monomer, polymer membrane material, solvent, pore-forming agent, initiator are mixed according to proportion, constant temperature stirring, under nitrogen atmosphere and polymer membrane material conventional dissolution temperature, initiate in-situ copolymerization, form casting solution containing strong hydrophobic crosslinkable copolymer A-B, then the casting solution is made into nascent liquid membrane, through short time spray treatment accelerates liquid membrane surface interface phase separation, then the membrane is immersed in coagulation bath and crosslinked and solidified, to obtain persistent super-hydrophobic uniform pore separation membrane, its water contact angle is greater than 150°, and the tensile strength is greater than 3.5 MPa. The preparation method is simple in operation, and the reaction conditions are mild. In the process of membrane preparation, the membrane material is persistent super-hydrophobic and the pore size is uniform, which promotes the improvement of the membrane anti-wetting ability.

The application discloses a method for separating organic salt by Donnan dialysis coupled with membrane distillation process, which comprises the following steps: placing acid wastewater and electrocatalytic synthesis liquid on both sides of a cation exchange membrane in Donnan dialysis, wherein the electrocatalytic synthesis liquid is an alkaline organic aqueous solution; separating a first side chamber and a second side chamber by using a hydrophobic membrane in a membrane distillation process, wherein the solution in the first side chamber is a KOH solution, and the solution in the second side chamber is the electrocatalytic synthesis liquid, and the electrocatalytic synthesis liquid is circulated in the membrane distillation process and the Donnan dialysis; and using a KOH solution as an electrolyte in electrolytic water, and circulating the KOH solution in the first side chamber and the electrolytic water. The method realizes synchronous solution of organic salt dealkalization and acid wastewater neutralization, and reduces the crystallization separation step in the traditional process.

This invention discloses a spiral-wound electrochemical carbon capture membrane distillation assembly, a lithium extraction system, and a lithium extraction method, belonging to the field of membrane separation technology. The spiral-wound electrochemical carbon capture membrane distillation assembly includes a shell and a cylindrical electrode and a co-wound assembly disposed within the shell. The co-wound assembly includes a conductive membrane bag assembly, an aeration guide net assembly, and an electrolyte bag assembly, which are stacked and co-wound in a spiral shape. The aeration guide net assembly is used to introduce high-temperature CO2 gas. The conductive membrane bag assembly can permeate, collect, and discharge water vapor. The electrolyte bag assembly is used to carry the electrolyte, and the electrolyte bag assembly and the conductive membrane bag assembly are respectively connected to the positive and negative terminals of an external power supply to perform anodic and cathodic electrochemical reactions, respectively. The cylindrical electrode is disposed outside the co-wound assembly and connected to the negative terminal of the external power supply. This invention can solve the problem of membrane interface scaling and has advantages such as low cost and negative carbon emissions.

This invention relates to the field of separation membrane technology, and particularly to a photothermal nanofiber membrane capable of retaining volatile organic compounds (VOCs), its preparation method, and its applications. This photothermal nanofiber membrane employs a multi-structure synergistic design to comprehensively optimize the overall performance of membrane distillation. In the gradient wettability structure of the photothermal nanofiber membrane, the hydrophobic layer, with its low thermal conductivity, suppresses heat conduction loss and alleviates temperature polarization; the hydrophilic layer, through its hydration effect, suppresses solute enrichment and alleviates concentration polarization; the nano-thin-coated PDA photothermal layer achieves efficient photothermal conversion through the light trapping effect, while simultaneously providing sufficient anchoring points for the loaded defective UiO-66 nanoparticles; the synergistic effect of each functional layer achieves multifunctional integration of thermal management, anti-fouling, photothermal conversion, and VOCs retention, comprehensively improving the operating efficiency and stability of the membrane distillation system. The preparation method provided by this invention offers strong process controllability and possesses good reproducibility and potential for large-scale application.

A PVT heat pump vacuum membrane distillation wastewater treatment system belongs to the field of energy saving and environmental protection. The system comprises a photovoltaic-thermal (PVT) heat pump, a vacuum membrane distillation assembly, a circulating pump, a vacuum pump and other equipment. Its characteristics are as follows: firstly, industrial wastewater is pretreated into a dilute solution, which is driven into a first heat exchanger by the circulating pump, and the dilute solution is preheated by using the heat energy generated by photovoltaic power generation. Secondly, the dilute solution is evaporated in the vacuum membrane distillation assembly, the produced secondary steam is compressed by a compressor to increase temperature and pressure, and then enters a second heat exchanger to condense and release heat to the concentrated liquid, and the heated concentrated liquid returns to the feed water tank for continuous concentration, and is recycled after reaching the required concentration. The invention makes full use of photovoltaic-thermal and secondary steam latent heat, meets the energy demand of the vacuum membrane distillation wastewater treatment process, has the advantages of high energy utilization efficiency, low operation cost, strong operation stability and the like, and is suitable for industrial heating, wastewater treatment and other fields.

The greenhouse brackish water desalination irrigation system coupled with membrane distillation and humidification-dehumidification technology belongs to the field of rural agricultural water resources utilization. The system couples membrane distillation and humidification-dehumidification technology to improve the efficiency of brackish water desalination and regulate the microenvironment in the greenhouse; solar energy is used to heat the underground brackish water to drive the membrane distillation subsystem to utilize brackish water desalination for agricultural irrigation. The high-temperature brackish water with residual heat and low-temperature fresh water discharged from the membrane distillation subsystem are introduced into the wet curtain and condenser in the greenhouse, and the brackish water is desalinated by the humidification-dehumidification technology to improve the utilization rate, and the high-temperature brackish water introduced into the wet curtain is used to heat the low-temperature air, which helps the greenhouse to maintain an environment suitable for crop growth in winter. A regenerator is provided in the system to preheat the underground brackish water with the brackish water discharged from the membrane distillation subsystem with residual heat, which reduces the installation area of the solar collector and the cost of the system.

This invention relates to the field of industrial water treatment and waste heat recovery, and discloses a closed-loop cooling water purification and cascaded thermal energy utilization system. The system includes an energy cascaded coupling utilization module for graded recovery of the thermal energy of high-temperature cooling water into electrical energy, cooling energy, and thermal energy; a high-temperature current-varying capacitor deionization dynamic matrix purification module for purifying the cooling water; a sensing and collaborative control module for monitoring energy output and purification unit status, and determining when to perform regeneration; and a low-temperature membrane distillation zero-discharge module. The sensing and collaborative control module initiates regeneration of the purification module only when energy is abundant, based on a regeneration decision algorithm. The low-temperature membrane distillation zero-discharge module utilizes the waste water thermal energy at the end of the energy cascade module to treat the high-concentration concentrate discharged from the purification module, recovering pure water and achieving zero discharge. Through the synergistic effect of each module, this system achieves efficient cascaded energy utilization, intelligent operation, and a closed-loop water resource system.

The present application relates to the technical field of radioactive waste water treatment, and discloses a method for discharging radioactive waste water of a nuclear medicine department up to standard, which adopts a system comprising a temporary storage pool, a waste water pool, a purified water pool and a non-contact membrane distillation device. The method comprises the following steps which are cyclically executed according to a treatment period: radioactive waste water generated by the nuclear medicine department and concentrated liquid generated during operation of the non-contact membrane distillation device are both discharged into the temporary storage pool and mixed and temporarily stored. When the non-contact membrane distillation device stops operating, the waste water temporarily stored in the temporary storage pool is transferred to the waste water pool. Subsequently, the non-contact membrane distillation device is started, and the waste water in the waste water pool is purified, and the purified liquid is discharged into the purified water pool. The purified liquid is stored and decayed in the purified water pool, and is discharged after the radioactivity reaches a preset discharge standard. The present application can shorten the total time required to reach the standard, and greatly reduce the volume requirement and land area requirement of a large decay pool.

This utility model discloses a sampling device for vacuum membrane distillation, relating to the field of vacuum membrane distillation technology. It includes a support frame, a sampling container mounted on the support frame, and a connector on the sampling container for connection to a vacuum membrane distillation condenser. It also includes a conical hopper positioned below the sampling container, with a sealing plate at the outlet end of the hopper. A connecting plate is mounted on the sealing plate, and one end of the connecting plate has a control mechanism for controlling its movement. A control valve is mounted on the sampling container for opening or closing it. A connecting pipe is fixedly connected to the sampling container, and a vacuum pump is mounted at the end of the connecting pipe furthest from the sampling container, with the vacuum pump fixedly connected to the support frame. This sampling device for vacuum membrane distillation allows the distillation apparatus to remain under vacuum during condensate extraction, thereby improving distillation efficiency and product quality.

This invention discloses a method for preparing a coupled micro / nanofiber composite membrane distillation apparatus, comprising the following steps: 1. Preparing a hydrophilic PSA / SiO2 fiber membrane substrate; 2. Preparing a hydrophilic-hydrophobic modified composite membrane; 3. Photothermal / magnetic thermal modification: (1) Dissolving PEO powder in a mixed solution of water and alcohol, stirring evenly to obtain a mixed solution for later use; (2) Adding Mxene and CNT to the mixed solution to obtain a photothermal modified solution; (3) Uniformly dispersing Fe3O4 in a PVA solution to obtain a magnetic thermal modified solution; (4) Using an electrostatic spraying process, applying the photothermal modified solution to the surface of the hydrophilic-hydrophobic modified composite membrane, and simultaneously spraying the magnetic thermal modified solution to form a photothermal / magnetic thermal modified mixed layer on the surface of the hydrophilic-hydrophobic modified composite membrane, thereby obtaining a coupled micro / nanofiber composite membrane distillation apparatus. This invention can effectively shorten the water vapor mass transfer path while improving the membrane's permeation flux, anti-wetting performance, and overall separation efficiency, thereby improving distillation efficiency.

The application provides a hydrogel, a membrane assembly and a distillation method for membrane distillation, wherein the hydrogel takes polyurethane as a support material, polyvinyl alcohol is loaded on the polyurethane, or a reaction product of polyvinyl alcohol and sodium alginate, or a reaction product of polyvinyl alcohol, sodium alginate and carboxylated carbon nanotubes. The application utilizes the interaction between water and polymer in the hydrogel to change the hydrogen bond network and the state of water, so as to reduce the water evaporation enthalpy. The permeation flux of the system is improved without increasing the energy consumption, thereby reducing the specific energy consumption of water production, optimizing the operation condition, and providing a new strategy for solving the problem of low heat utilization rate of membrane distillation.

This invention discloses an ammonium chloride wastewater treatment device and method, belonging to the field of wastewater treatment technology. The treatment device includes a pretreatment unit, an MVR unit, and a membrane distillation unit connected in sequence. The MVR unit includes a heat exchanger, an evaporator, a crystallizer, and a separator connected in series. The inlet of the heat exchanger is connected to the outlet of the pretreatment unit, and the outlet of the separator is connected to the inlet of the membrane distillation unit. It also includes an MVR compressor. The inlet of the MVR compressor is connected to the secondary steam outlet of the evaporator, and the outlet of the MVR compressor is simultaneously connected to the heat source inlets of the evaporator and the heat exchanger. The ammonium chloride wastewater treatment device and method provided by this invention, through the cooperation of the pretreatment unit, MVR unit, membrane distillation unit, and MVR compressor, can achieve efficient utilization of waste heat, reduce the probability of scaling, and reduce system energy consumption.

A process for the electrolysis of water to obtain hydrogen comprises the following process steps: a) Providing an electrolyte solution (5) comprising water and at least 1 mol / l of at least one electrolyte, a feed solution comprising water, and an osmotic membrane distillation apparatus comprising at least three chambers, namely a feed chamber (21), a permeate chamber (22) and an electrolysis chamber (11), wherein the feed chamber (21) and the permeate chamber (22) are separated by a porous hydrophobic gas-permeable membrane (27) and the feed chamber (21) contains feed solution and the permeate chamber (22) contains electrolyte solution (5), b) Performing an osmotic membrane distillation, wherein water evaporates in the feed chamber (21), passes as water vapor through the membrane (27) and condenses into the electrolyte solution (5) in the permeate chamber (22), and c) Electrolysis of water of the electrolyte solution (5) in the electrolysis chamber (11), yielding hydrogen and oxygen.

This invention relates to the field of DCMD module desalination performance testing, specifically a method for analyzing the desalination performance of a seawater desalination system based on engine waste heat recovery. This invention constructs a closed-loop thermal-mass-phase change model driven by engine waste heat and centered on the membrane interface for steady-state analysis of the seawater desalination process; it also comprehensively considers the coupling relationships between multiple parameters. These parameters collectively affect vapor pressure and heat transfer processes, thereby enabling the testing and analysis of the desalination performance of the seawater desalination system. By introducing the Knudsen number of the permeate membrane as a criterion, the microscopic mechanism of water vapor diffusion during membrane distillation is correlated with macroscopic performance testing. Based on the identification of diffusion types, the corresponding physical model is selected to calculate the mass transfer coefficient, improving the accuracy of mass flux and subsequent desalination rate calculations. This allows for real-time testing of the desalination performance of the DCMD module in the seawater desalination system with high accuracy.

This invention discloses a photothermal distillation membrane assembled layer by layer using silver-intercalated MXene, its preparation method, and its application. It belongs to the field of photothermal membrane distillation system application technology. The preparation method includes the following steps: adding silver nitrate solution and water to a single-layer MXene nanosheet dispersion and then ultrasonically mixing; then mixing with a p-PVDF membrane with one hydrophilic side; after in-situ evaporation, obtaining an Ag@MXene-PVDF membrane; coating its surface with a polyvinyl alcohol solution and then drying to obtain an s-Ag@MXene-PVDF membrane, i.e., the photothermal distillation membrane. This invention also discloses the photothermal distillation membrane prepared by the above method and its application in seawater desalination. The photothermal distillation membrane prepared by this invention exhibits excellent photothermal conversion efficiency, high water flux, and long-term stable operation. It provides a new approach for developing multifunctional photothermal distillation membranes and has broad application prospects in the field of seawater desalination.

The present application relates to a kind of high-efficiency flocculation+ozone catalysis+membrane distillation combined process, it is applicable to the treatment of high-salinity wastewater, especially coal-fired power plant desulfurization wastewater and coal chemical wastewater.The process ingeniously combines high-efficiency flocculation, ozone catalysis and membrane distillation technology, add special chitosan-based flocculant in flocculation stage, with its excellent adsorption and flocculation efficiency, effectively remove suspended solids and heavy metal ions in wastewater;Ozone catalysis stage is through the addition of self-developed ternary composite catalyst, accelerates the process of ozone decomposition, thereby deeply purifying organic pollutants;In the membrane distillation stage, use self-made antifouling and anti-wetting composite membrane for efficient desalination and concentration, finally reach the efficient purification and reuse of high-salinity wastewater.The process can significantly improve the treatment effect of wastewater, reduce the concentration of salt and harmful substances in wastewater, also reduce the operating cost, suitable for large-scale industrial wastewater treatment.

This invention belongs to the field of metallurgical wastewater treatment technology and discloses a method for the resource utilization of cold rolling pickling waste liquid, including the following steps: 1) The pickling waste liquid is collected and enters a waste liquid collection tank, where it is homogenized and adjusted; 2) The homogenized and adjusted pickling waste liquid is first subjected to a security filter for preliminary impurity removal, and then subjected to an ultrafiltration membrane module for deep impurity removal to obtain ultrafiltration permeate; 3) The ultrafiltration permeate is concentrated by a membrane distillation system to obtain membrane distillation concentrate; 4) The membrane distillation concentrate is first subjected to a primary chelating resin for coarse removal of metal ions, and then subjected to a secondary chelating resin for fine removal of metal ions to obtain purified acid, which is used as acid for cold rolling pickling. This invention purifies the pickling waste liquid by removing impurities and concentrating it to meet the requirements for pickling acid, and then returns it to the rolling mill for reuse, reducing the discharge of pickling waste liquid and the consumption of acid in the pickling and rolling mill.

This invention discloses a micro-electric field-stimulated coupled anaerobic membrane distillation reactor and its method for enhancing methanogenesis, belonging to the field of wastewater treatment and resource utilization technology. The reactor includes an anaerobic reaction tank, a micro-electric field stimulation unit, a membrane distillation assembly, a temperature control unit, an influent unit, a condensation and collection unit, a vacuum pump, and a biogas collection unit. The micro-electric field stimulation unit consists of a composite anode, a carbon brush cathode, and an external DC power supply, applying a micro-electric field of 0.3~0.8V. The method includes inoculating anaerobic sludge, adding kitchen wastewater and / or landfill leachate, starting membrane distillation at 45~65℃ and applying a micro-electric field, gradually increasing the proportion of landfill leachate, collecting biogas, and monitoring methane content. This invention utilizes a low-voltage micro-electric field to promote interspecies electron transfer, achieving a methane yield exceeding 340mL / gCOD at a 1:1 ratio of kitchen wastewater to landfill leachate, approximately 40% higher than the control, and enhancing the system's resistance to shock loads and metabolic recovery capacity.

The application provides a modified heat carrier, a film assembly and a distillation method for heat-conducting vacuum film distillation. The surface of an aluminum heat carrier is modified by a graphene heat dissipation coating and / or a super-hydrophobic silicon dioxide coating to prepare a novel composite heat carrier which can effectively improve the heat and mass transfer process of the system and improve the performance of the heat-conducting vacuum film distillation.

This invention discloses a scaffold composite membrane constructed from electrospun polysulfone on a liquid polyvinylidene fluoride substrate, its preparation method, and its application, belonging to the field of membrane distillation technology. The composite membrane comprises a CAU-10-NH₂-doped PVDF substrate and a CAU-10-NH₂-doped PSF fiber scaffold layer constructed in situ on its surface using a handheld electrospinning gun before solvent-induced phase inversion. This method avoids the interlayer delamination problem of traditional multilayer membranes, utilizes PSF fibers to provide mechanical support and form a high-roughness surface, and combines the hydrophilicity and antifouling properties of CAU-10-NH₂ to significantly improve water flux, antifouling properties, and long-term stability. In simulated seawater desalination tests (3.5 wt% NaCl, 70 ℃), the membrane flux reached 42.8 L·m⁻²·h⁻¹, with a rejection rate of 99.2%. In the anti-wetting test (with SDBS surfactant), the flux remained stable at 32 L·m⁻²·h⁻¹ for 900 min, with a rejection rate of 99%. In the antifouling test: with humic acid (HA) as the pollutant, the flux reduction rate of the pure PVDF membrane was 75.76%, while that of the composite membrane of this invention was only 24.23%, with a flux recovery rate of 92.97% (pure PVDF membrane 67.69%); with sodium alginate (SA) as the pollutant, the flux reduction rate of the pure PVDF membrane was 85.70%, while that of this invention was only 30.38%, with a flux recovery rate of 89.98% (pure PVDF membrane 52.81%). The preparation process of this invention is simple, the structure is controllable, and the performance is excellent, showing good application prospects.

The vacuum membrane distillation module comprises a central core, a plurality of hollow fiber membranes, a shell that cylindrically houses the bundle of hollow fiber membranes and the central core, at least one circumferential holding structure that holds the ends of the plurality of hollow fiber membranes, at least one end cap that houses at least one circumferential holding structure, at least one support rod that extends in the longitudinal direction, and a potting material held between (i) an inner boundary formed by the outer circumferential surface of the central core and (ii) an outer boundary formed by the inner circumferential surface of at least one circumferential holding structure. Furthermore, at least one of (i) the outer circumferential surface of at least one end of the central core and (ii) the inner circumferential surface of at least one circumferential holding structure is provided with a structure for strengthening the bond with the potting material.

The present application relates to the field of ammonium chloride concentration crystallization, and particularly relates to a kind of ammonium chloride concentration crystallization system and method.The ammonium chloride concentration crystallization system of the present application includes raw material buffer device, dosing device, concurrent multi-effect membrane distillation device, countercurrent multi-effect membrane distillation device, heat exchange device, cooling device, centrifugal device and centrifugal liquid buffer device.The ammonium chloride concentration crystallization system of the present application can improve the crystallization efficiency and purity of ammonium chloride by the cooperation of each device, and the obtained ammonium chloride crystal and distilled water can be directly reused, the system is simple, corrosion resistant, and has high degree of engineering application, good energy saving and emission reduction effect.