Relevant information shows that drinking water is an important way for the human body to obtain fluorine, which can reach 65% of the human body's fluorine intake.Therefore, the World Health Organization (WHO) suggests that the fluorine content of drinking water should be 0.5-1.0mg/L, and the standard limit of fluorine in urban drinking water should be 1.0mg/L, and the standard limit of fluorine in rural drinking water should be 1.2mg/L.

Fluorine is one of the most important trace elements in the human body. Fluorine is widely distributed in nature in the form of fluoride ions. It is closely related to human life activities and the metabolism of teeth and bones. Small amounts of fluoride can increase the resistance of tooth enamel to bacterial acid erosion and prevent dental caries. However, excessive intake of fluoride can cause fluorosis, dental fluorosis, bone fluorosis, kidney, liver and brain damage, abnormalities of the immune system and diseases such as pulmonary edema and pulmonary hemorrhage.

It is understood that nanofiltration technology is a membrane separation technology of reverse osmosis and ultrafiltration. Its surface is usually negatively charged, and its pore size is usually 1-2 nm.The molecular level of the dynamic sink structure can be controlled by molecular level structure design, which is realized by the combination of charge, pore size and other factors. Differential isolation nanofiltration membrane is a pressure-driven membrane that effectively removes toxic and hazardous substances at very low operating pressures and effectively retains beneficial mineral elements in the water. It is one of the hotspots in the field of water treatment in the world today.

Nanofiltration technology removes fluoride from water. On the one hand, the negative electronegativity of the nanofiltration membrane material enhances its electrostatic repulsion of negatively charged ions (F-), and on the other hand, the hydration radius of F- is usually larger than the pore size of the nanofiltration membrane, which can effectively retain F-.

Nanofiltration defluoridation technology is both safe drinking water and healthy drinking water in line with the World Health Organization and national drinking water standards. Practice has proved that nanofiltration technology can achieve selective filtration, effectively remove residual organic compounds, disinfection by-products, heavy metals and other harmful substances in the water, while retaining the mineral elements needed by the human body, more conducive to human health. Healthy, suitable for people to drink for a long time, is to ensure the safety of drinking water technology.

So what are the sources of fluoride in drinking water? Generally speaking, its sources can be divided into two categories: one is natural fluoride-containing deep well groundwater, which is more common in rural areas. In the natural state, the fluoride content of groundwater is generally 1.0-3.0mg/L, and the fluoride content of groundwater in high-fluoride areas can be up to 10-20mg/L, while the fluoride content of drinking water in our country is controlled to be 1mg/L or less. Residents of high-fluoride areas have been drinking high-fluoride water for a long time, and the second is water pollution caused by improper discharge of fluorine and its compounds. Industrial fluorine-containing wastewater produced by metal processing and electroplating, as well as the scrubber water for treating fluorine-containing waste gas, when discharged into the environment, causes different degrees of pollution to water and soil, seriously threatening people's health. and life safety.

Defluoridation of drinking water is one of the most challenging issues in water treatment. Nanofiltration, as a new membrane separation technology with the advantages of stable effluent water quality, selective separation and proper retention of mineral elements required by the human body, is considered to be the ideal technology for fluoride removal. Drinking water treatment technology.

More than 200 million people around the world drink fluoride-rich water, and nearly 80 million of them are in China, according to DeutscheVoice.com. In recent years, there have been numerous incidents of excessive fluoride in China's drinking water. Whether it is “a small area of deep well water tap water, triple excess fluoride” caused by 13 years of shock, or “Liaocheng part of the area of fluoride poisoning” caused by the panic, can explain “drinking water fluorosis ”The problem of fluorosis in drinking water. Drinking a cup of safe and healthy water has become an urgent problem for more and more families.