Consult about the use of ultrafiltration membranes in wastewater treatment

1.The ultrafiltration membrane can intercept bacteria, but can not kill bacteria, no matter how good the rejection rate of the ultrafiltration membrane can not ensure that there are no bacteria in the clean area for a long time, which will directly affect the effluent quality, so it is necessary to regularly sterilize the turnover environment and the filtration system, and the sterilization operation cycle depends on the quality of the raw water supplied.

2.The number of components used in the filtration system is determined according to the total design permeability, and the nominal hourly water production of each module refers to the permeability rate of pure water, which refers to the use of pure water as the test medium, and the pure water does not have the problem of clogging caused by solutes to the ultrafiltration membrane. However, the water permeability rate of the device gradually decreases with the operation time, but it can basically return to a relatively stable value after cleaning.

In addition, the permeability of ultrafiltration components is also affected by factors such as temperature, pressure, liquid concentration, and turbidity of feed water.

3.Since each ultrafiltration component is added with protective fluid before leaving the factory, the protective fluid in the component should be thoroughly rinsed before use, and the permeate discharge valve of the system should be fully opened during both low-pressure and high-pressure washing.

4.Because ultrafiltration components are precision equipment, they should be careful when using and installing, and they should be handled with care, and they should not be broken. If the component is out of use, it should be rinsed with clean water first, and then disinfected and sterilized with formaldehyde aqueous solution, and sealed.

For example, in winter, the module should be frost-proofed.

5.Before using hollow fiber ultrafiltration membrane, it is necessary to carefully read the instructions for use and operate according to the application process of ultrafiltration membrane in water treatment.

The working pressure of the ultrafiltration membrane is generally 60, and the permeation flux of ultrafiltration is 1 500 l m2·h, and the permeation rate is 1 100 l m2·h. According to the use experience, the influencing factors of ultrafiltration permeability flux include feed flow rate, operating pressure, operating temperature, operation cycle and membrane cleaning and maintenance, etc., which can be reasonably selected through the process technical parameters to keep the ultrafiltration membrane in good working condition and ensure the stability and reliability of effluent quality.

Ultrafiltration membranes are widely used in the advanced treatment of industrial wastewater and process water, such as the concentration, purification and separation of macromolecular substances in the chemical, food and pharmaceutical industries, the sterilization of biological solutions, the separation of dyes in printing and dyeing wastewater, the preparation of glycerol in petrochemical wastewater, silver in photochemical wastewater and ultrapure water. In addition, it can also be used for:

1. Electroplating wastewater treatment.

The power industry produces a large amount of wastewater, and contains a large amount of hexavalent chromium, copper, nickel and other metals, toxic, very low biological, iron oxide electrolysis is often used in actual work, etc., but iron oxide will produce a large amount of sludge, sludge still needs further treatment: although the electrolysis method can treat electroplating wastewater well, but the cost is high, not suitable for widespread promotion. The use of ultrafiltration membranes can also reduce the contamination of permeable membranes and improve their service life.

2. Treat oily wastewater.

The main ** oily wastewater includes ** leakage, slaughterhouse wastewater and domestic wastewater, etc. The main components are slick oil, dispersed oil, emulsified oil and heavy oil, etc. The commonly used oily wastewater treatment unit is a grease trap, but the emulsified oil cannot be treated, so air flotation is usually used for shaft auxiliary treatment.

Due to the large molecules of emulsified oil, ultrafiltration membrane technology can be used to make oily wastewater pass through the ultrafiltration membrane under pressure conditions, so as to intercept emulsified oil and other macromolecular pollutants with high removal efficiency.

3. Utilization of food industry wastewater.

In addition to improving water quality, ultrafiltration membrane technology can also concentrate and improve a large number of useful solids for applications in the food industry. Food industry wastewater contains a large amount of fat, protein, starch, yeast, etc., if these substances are discharged into the environment, not only will cause environmental pollution, but also cause a lot of waste, so the use of ultrafiltration membrane technology constitutes a useful interception of wastewater, at the same time, the separation of BOD and COD of water from the water, can bring greater economic benefits to the enterprise.

Ultrafiltration membrane is a membrane separation technology widely used in the field of water treatment, and its main function is to purify and improve water quality by effectively filtering microorganisms, suspended solids, organic matter, particulate matter and other impurities in water, and ensure the safety and stability of water quality. Specifically, it can effectively remove microorganisms such as colloidal substances, bacteria and viruses in the water to meet the requirements of the effluent standard, and at the same time ensure the stability of water quality, making the water more clear and transparent, better tasting and healthier. Therefore, in the fields of drinking water, pharmaceutical production, chemical industry, etc., ultrafiltration membranes are more and more widely used, bringing great convenience and benefits to people's daily life and production activities.

The whole house ** water purification can solve the water quality problem at home in one step, which can not only ensure the safety and health of our daily drinking water, but also protect the water wading appliances at home from water quality problems. Since then, the people who drink directly at home, wash vegetables and cook, brush their teeth and wash their faces, take a bath and do laundry, and even flush the toilet are purified water, which feels more refreshing!

The top ten famous brands of water purifier Lisheng water purification for home users to provide the whole house ** water purification scheme is mainly composed of Lisheng pre-filter + ** ultrafiltration water purifier + ultrafiltration companion + water softener + instant hot water dispenser. Lisheng** ultrafiltration water purifier is the core of the water purification system, with an accuracy of up to micron PVC ultrafiltration membrane element, which can efficiently filter out harmful impurities such as sediment, rust, colloids and bacteria and microorganisms in tap water, while retaining beneficial minerals and trace elements in the water, providing sufficient healthy drinking water for the whole house.

In the Lisheng whole-house water purification system, the tap water will be centrally purified at the main pipe through the Lisheng ultrafiltration membrane water purifier, and then flow to different water places, and according to the water needs and water quality characteristics of different water places, different terminal ultrafiltration partners are installed. For example, the end of the kitchen is equipped with a deodorization partner to absorb the residual discoloration and odor in the water, so that the drinking water tastes more sweet and refreshing; Install a terminal water softener in the bathroom to soften the water quality and avoid the damage caused by mineral ions in the clean water; You can also install a pre-filter at the front end of the ultrafiltration water purifier to coarsely filter the drinking water in the whole house, reduce the purification pressure of the ultrafiltration water purifier, and effectively extend the service life of the water purifier.

UF ultrafiltration can no longer be used when the membrane is dry. The ultrafiltration membrane is generally immersed in the protective solution for sealing and storage before use, so as to prevent the shrinkage of the wet membrane after dehydration, and the membrane pores become smaller, so that the membrane structure is damaged and the water flux is reduced. Therefore, please do not let it out of the protective solution before use.

The wet membrane will shrink and deform due to dehydration, which will greatly reduce the membrane pores, or destroy the membrane structure, and at the same time make the texture of the membrane brittle, and even make the filtration of the membrane completely invalid. The natural dehydration and drying of the ultrafiltration membrane will lead to the collapse of the membrane pores, which will seriously affect the permeability and mechanical strength of the membrane. Therefore, the membrane needs to be treated in a dry state.

Reverse osmosis can block all kinds of ions and various organic molecules larger than water molecules, only allow water molecules to pass through, and the diameter of the membrane pore is less than 1 nanometer. Due to the small diameter of the membrane pores, the requirements for inlet water are very high, just like the fine sieve is not used to sieve the powder particles containing a large number of large particles, otherwise not only the separation efficiency is not high, but also easy to cause rapid blockage. In terms of sewage treatment, it is mainly suitable for treating electroplating wastewater, and the heavy metal ions in it are concentrated and then further treated or utilized.

Ultrafiltration can only block substances above 5 nanometers, such as bacteria, colloids, proteins, some dyes, etc., but cannot block viruses, various ions and small molecule organic substances. As with reverse osmosis membranes, influent water also requires the removal of substances larger than 5 microns in advance. In terms of treating sewage, it can be used to treat electrophoretic paint wastewater, ** paint, and in recent years, the method of directly treating domestic sewage with ultrafiltration membrane is becoming a research hotspot.

1. About pretreatment:

Different membrane treatment processes have different requirements for pretreatment, the higher the filtration precision of the membrane, the higher the requirements for pretreatment, the worse the water quality, and the higher the requirements for pretreatment. If it is sewage, on the basis of traditional sewage treatment, activated sludge method + ultrafiltration + reverse osmosis (nanofiltration) can be used, and the pre-process is the pretreatment of the post-process process; If it is groundwater, multi-media filter + ultrafiltration + reverse osmosis (nanofiltration) can be used, and the pre-process is pre-treated for the post-process pretreatment.

The pretreatment selection is based on the quality of the pretreated permeate that meets the influent water quality of the membrane treatment equipment you choose.

2. Membrane treatment selection: The selection of membrane treatment equipment is based on the water quality index you need, because the water quality of the membrane equipment you choose should meet your water quality needs!

3. Follow-up treatment process: The follow-up treatment process of membrane treatment mainly includes the treatment of concentrated water, the adjustment of the pH of the membrane treatment produced water, etc., which should be determined in combination with the actual situation of the site and the water quality index.

These two books are available online, you can take a look, it is very helpful for your improvement, this is a very wide subject, it is not simple to explain clearly, as long as you usually pay attention to accumulation, there will be a great improvement! Good luck with you!

Membrane treatment is used in many fields in water treatment, and the selection of pretreatment is mainly based on the dirt-holding capacity, and the selection of nanofiltration, ultrafiltration, and reverse osmosis is based on what kind of effluent index is the basis for selection. The choice of follow-up treatment is basically the matching design of the pool capacity.

There are too many questions, so let's look at professional books.

Reverse osmosis membranes. is a simulated creature.

Semi-permeable to this film.

made of artificial with certain characteristics.

Semi-permeable membranes. General use.

Polymer materials.

Made. As. Cellulose acetate.

Touch, aromatic gathering. Hydrazide. membranes

Aromatic polyamides.

membranesThe diameter of the surface pores is generally between, and the size of the permeability is the same as that of the membrane itself.

Chemical structure. Relate. Some polymer materials have good repulsion to salt, but the permeability of water is not good. The chemical structure of some polymer materials has hydrophilic genes, so the permeability of water is relatively fast.

Reverse osmosis principle.

Ultrafiltration membranes. It is a kind of perforation with the same aperture specification and the rated pore size range is micron.

Filtration membranes. By applying the appropriate pressure on one side of the membrane, solute molecules smaller than the pore size can be sieved out to separate large amounts up to 500

Dalton. Atomic mass unit.

Particles larger than 10 microns in size. Ultrafiltration membranes were the first to be developed.

Polymer separation membranes.

One of them, in the 60s.

Ultrafiltration unit. Industrialization was achieved.

The principle of ultrafiltration. Reverse osmosis membranes have the following characteristics:

at high flow rates. The next should be.

With high efficiency. Salt rejection rate.

With high. Mechanical strength.

and service life.

3) It can function under low operating pressure.

4) Able to tolerate the effects of chemical and biochemical effects.

It is less affected by factors such as pH value and temperature.

6) The production of raw materials is easy, easy to process, and low cost.

Application characteristics of ultrafiltration membranes:

1) There will be no qualitative change in the ultrafiltration process, and it can be at room temperature.

Stable operation. 2) The equipment has a delicate structure, small footprint and easy to operate.

Equipment. Separation process.

Equipment. Degree of automation. High.

It can classify substances of different molecular weights.

5) Strong adaptability to water quality and wide range of applications.

Scope of application of reverse osmosis.

Electric power, petrochemical, iron and steel, electronics, medicine, food and beverage, municipal and environmental protection industries, in seawater and.

Brackish water. Talk about the boiler feed water.

Industrial pure water. and electronic grade.

Ultrapure water preparation.

Drink purified water.

Wastewater treatment. and special separation process.

Application range of ultrafiltration membranes.

Water. Yu Chao.

In the pure water preparation process, it is used as the terminal treatment of reverse osmosis pretreatment and ultrapure water, and industrial water.

Useful. Separation of bacteria, heat sources, colloids, suspended impurities and macromolecular organic matter; purification of drinking water and mineral water; Fermentation

Enzymes. Industry;

Pharmaceutical industry. concentration, purification and clarification; fruit juice concentration and separation; Soybeans, dairy,

Sugar industry. separation, concentration and clarification of wine, tea, vinegar, etc.;

Industrial wastewater. And.

Domestic sewage. The purification of water with **, electrophoretic paint.

Target**.