The second is ultrafiltration (UF) technology. The core of ultrafiltration water purifier is ultrafiltration membrane, which is a membrane separation technology using pressure difference. Ultrafiltration water purifier is characterized by no electricity and no waste water, and the filtered water is mineral water. It can filter out harmful substances such as rust, sediment, colloid, bacteria, virus and macromolecular organic matter. In water, and can retain some mineral elements beneficial to the human body. However, ultrafiltration technology cannot remove heavy metals from water, so it is not recommended to drink pure water directly. The recovery rate of water in ultrafiltration process is as high as 95%, which is convenient to realize forward flushing and backward flushing, not easy to block, and has a relatively long service life.
The third is RO membrane reverse osmosis technology. This technology is now widely used in the filtration of water purifiers, which can filter out almost all impurities (including harmful and beneficial) in water, only allowing water molecules to pass through, and filtering out pure water that can be directly drunk. The water purifier adopting this filtration technology needs electricity and wastewater, and the ratio of wastewater is generally 1: 3 (that is to say, purifying one cup of clean water needs to discharge three cups of wastewater, which is especially a waste of water resources), and it also needs a water storage tank (because this membrane has a small pore size and a small water output, it needs to store water first before it can supply domestic water, so that the water from the water purification faucet is not fresh water, but is prepared in advance and stored in the water tank). The water purified by this technology is pure water, and all harmful and beneficial substances have been filtered out, which is very clean. Some people call this water "bone scraping water". Children are prone to rickets and the elderly are prone to osteoporosis after drinking for a long time, which has a prominent negative effect on growing teenagers and the elderly. Therefore, it is not advisable to drink pure water for a long time. Pure water is the cleanest water, but not the best water! It is generally used to make drinking pure water, industrial ultrapure water and pharmaceutical ultrapure water. Reverse osmosis technology needs pressurized power supply, and the utilization rate of water is low.
When water lacks some or some elements necessary for human life, it will affect human health. For example, in some areas, water is short of iodine, and drinking this water for a long time will lead to "big neck disease", which is medically called "endemic goiter". When water contains harmful substances, it is more harmful to human body, and carcinogens are brought into human body through water and food. It is reported that the incidence of cancers such as liver cancer and gastric cancer in people who drink polluted water is about 6 1.5% higher than that in people who drink clean water.
The fourth is nanofiltration (NF) technology. The water purifier using nanofiltration technology has been controversial since it was put on the market. Its filtration accuracy is between ultrafiltration and reverse osmosis, and its desalination rate is lower than that of reverse osmosis. It is also a membrane separation technology that requires electricity and pressure, and the water recovery rate is low. It is called "nano water" and "small molecular water" in the market, which is conceptual and belongs to mineral water in essence. Now this technology is gradually indifferent, and it is generally used for the manufacture of industrial pure water.
The fifth is maze technology. This technology is only used in the British royal family and Haier Strauss water purifier. The core of maze technology is to filter out harmful substances in water, while retaining calcium and magnesium ions and trace elements beneficial to human body. Three filter elements have six-stage filtration function. The advantage of labyrinth technology is that the contact area and contact time between water and filter element and purification material can reach 99% under the action of water gravity, which is temporarily impossible for other water purification technologies. Because of the integrated filter element, the size of the water purifier is greatly reduced, and there is no cylinder and slim body. The appearance of the water purifier is more exquisite and compact, and the installation is more casual.