| Fluoride is one of the trace elements essential for human beings, wich is important for the Formation of teeth and bones at the normal level. However, its concentration in drinking water should not be too high. If it was absorbed excessively for a long period, it can cause dental fluorosis, severe skeletal fluorosis for worse or even paralysis resulting in the loss the labor capability. Currently, many countries face the problems of excessive fluoride in drinking water. In China, such problem is more severe. Drinking water of high fluoride concentration is mainly distributed in Hebei, Shandong, Inner Mongolia, Xinjiang Province, the vast rural and remote areas. Therefore, the problem of high fluoride water has become urgent to be solved all around the world. In this paper, the best modification methods of Bio-F were determined, the absorbing process was tested, and the adsorption mechanism was investigated.By the modification of the beaker experiments and practical application of Bio-F, initially identified 10% phosphoric acid (5:8) 24h before 10% sodium hydroxide (5:3) 24h of the modification.This study screened the surface structure and fluoride adsorption mechanism of Bio-F were analyzed by using SEM, BET, FT-IR, and XRD. The results showed that BET surface area of Bio-F was reduced after F- adsorption from 12.411m2·g-1 to 10.692m2·g-1. The average pore volume of Bio-F was 0.004 cm3·g-1 and the most probable pore size was 1.88nm. The process of F" adsorption of Bio-F includes ion exchange and adsorption. The F- adsorption process includes physical adsorption and chemical adsorption. Analysis by XRD suggested fluorine ion was possibly formed as Ca10 (PO4)5 CO3 (OH) F on the surface of Bio-F by ion exchange. |
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