Development prospect of membrane separation technology

Many people may not understand what membrane separation technology is. Modern membrane technology can turn seawater into fresh water and sewage into clean water, which has become a high-tech with magical effect and wide application. Human beings have a long history of understanding the membrane. As early as the mid-18th century, it was discovered that there was a semi-permeable membrane (later called separation membrane) in nature. Later, people further realized that semipermeable membranes widely existed in human bodies and various animals and plants.

After food and water enter the human body and are digested, the human body separation membrane quickly separates the harmful substances, and melts the beneficial substances such as oxygen, protein, fat and inorganic salts into the blood and transports them to all parts of the body. Therefore, the metabolic process of human body is a membrane process. After entering the 20th century, people began to study the membrane process systematically. So what is membrane separation technology? What is its principle?

The so-called "membrane" is actually an organic polymer or inorganic material with special selective separation function, which can separate the liquid into two parts that are not connected, so that one or more of them can penetrate and other substances can be separated. At present, the commercialized membranes are cellulose acetate, polysulfone, polyamide, polypropylene, polytetrafluoroethylene, polyester, porous aluminum membrane, ceramic membrane and metal composite membrane. The separation mechanism of the membrane is either based on the different molecular size of the permeate (sieving effect), or on the difference in charge of the separated substance (electrochemical effect), or depends on the physical and chemical characteristics of the separated substance (solubility effect). When a solution is separated by a diaphragm, the method of making solute pass through the membrane is called dialysis, and the method of making solvent pass through the membrane is called osmosis. The driving force for solute or solvent to penetrate the membrane is electromotive force, concentration difference or pressure difference.

For example, ultrafiltration is that after a certain pressure is applied to the solution, high molecular substances and colloidal substances are stopped by the semi-permeable membrane, while water and low molecular substances pass through the membrane, which is quite similar to the membrane process in the human body; Electrodialysis, on the other hand, uses ion exchange membrane to make ions in water migrate directionally under the action of external electric field, and selectively pass through ion exchange membrane with different charges, thus achieving the separation of solute and solvent. When it is used in seawater desalination, all kinds of salts in seawater can be separated from water under the drive of electric field force, and finally fresh water can be obtained.

From this point of view, the development prospect of membrane separation technology is still considerable. For more information about glass kiln construction and glass kiln design services, please visit our official website for detailed consultation.