Defluorination filter

The defluorination filter uses activated alumina adsorbent for defluorination treatment. Activated alumina adsorption filtration is currently the most mature, widely used, and effective method for fluoride removal.

The defluorination filter uses activated alumina adsorbent for defluorination treatment. Activated alumina adsorption filtration is currently the most mature, widely used, and effective method for fluoride removal. Activated alumina is a amphoteric substance with ion exchange properties in water, with an isoelectric point of approximately pH 9.5. When the pH of water is less than 9.5, it can adsorb anions, and when the pH of water is greater than 9.5, it can adsorb cations. Therefore, in acidic solutions, activated alumina is an anion exchanger with great selectivity for fluorine.

Fluoride removal filters are used in the production (domestic) water treatment of industrial and mining enterprises, rural safe drinking water and other industries, as well as as as pre-treatment equipment for ultrafiltration, nanofiltration, reverse osmosis, ion exchange, mixed bed, EDI and other equipment when the fluoride content in raw water is high.

The distribution range of fluoride containing groundwater in China is very wide. Long term consumption of water with high fluoride content can cause chronic poisoning, especially serious harm to teeth and bones. Mild cases of dental fluorosis can manifest as enamel damage, premature tooth loss, and other symptoms. Severe cases can cause bone and joint pain, even bone deformation, hunchback, and complete loss of labor ability. So the harm of high fluoride water is serious. The standard for drinking water in our country stipulates that the fluoride content shall not exceed 1mg/L.
Fluoride is widely present in nature. The fluoride content in natural water is generally between 0.3~0.5mg/L. The groundwater flowing through fluorine-containing ore layers can sometimes reach up to 2-5 mg/L.
Consuming a certain amount of fluoride daily from food and water is beneficial for preventing dental caries. Long term excessive intake of fluoride may lead to chronic poisoning. Mild cases may develop dental plaque and joint pain, while severe cases may experience bone development and loss of labor. The use of reverse osmosis (RO) membrane equipment may contain excessive fluoride, which directly affects the service life of the RO membrane. According to China's "Drinking Water Standards", the fluoride content in water is less than 1.0 mg/L.
At present, adsorption filtration is commonly used for defluorination. When the raw water flows through the defluoriner and the core filter layer inside the defluoriner - natural mineral filter material, the water comes into contact with the natural mineral filter material in the defluoriner and defluoriner. Through physical and chemical reactions - adsorption, fluorine is adsorbed on the surface of the adsorbent, generating insoluble fluoride, so that the fluoride content in the water reaches within 1.0 mg/L as specified in the national drinking water hygiene standard (GB5749-2006). When the defluorination ability drops to a certain limit (saturation), the adsorbent's defluorination ability is restored through regeneration with a rejuvenator.
The defluorination equipment consists of a defluorination tank, filter material, regeneration device, pipeline valves, etc. Different sizes of equipment can be selected according to different fluoride content and treatment water volume. The size of the defluoriner depends on the water volume and can be made of steel or fiberglass depending on the purpose. The defluorination device has a fixed bed and a fluidized bed. The water flow in a fixed bed is generally upflow, with a filter layer thickness of 1.1-1.5m and a filtration rate of 3-6m/h. The thickness of the moving bed filter layer is 1.8-2.4m, and the filtration rate is 10-12m/h