Study on improving the fluorine removal performance of Chitosan-Al2(SO4)3 2 (SO 4 ) 3 modified bauxite

To improve the fluoride removal performance of the bauxite, chitosan (CTS)-Al2(SO4)3 2 (SO 4 ) 3 modified bauxite was prepared to remove F-- from water. The fluoride removal rates of chitosan and unmodified bauxite were 16.36 % and 48.69 % respectively, and that of CTS-Al2(SO4)3 2 (SO 4 ) 3 modified bauxite could reach 98.28 %. The effects of addition amount of Al2(SO4)3 2 (SO 4 ) 3 and chitosan, bauxite calcination temperature, reaction time, adsorbent dose, initial F-- concentration and co-existing anions were investigated. SEM, FTIR, 77K N2 2 adsorption-desorption isotherm and XRD were used to analyze the bauxite before and after modification. The results showed that chitosan successfully combined with bauxite, and the morphological changes before and after modification were relatively small. The pseudo second-order kinetic model was more suitable for F-- adsorption process of on CTSAl2(SO4)3 2 (SO 4 ) 3 modified bauxite.