SYNTHESIS AND ADSORPTION PROPERTIES OF THE FUNCTIONAL RESINS FOR DEEP-REMOVAL OF AQUEOUS FLUORIDE

In this paper,two kinds of novel resins(XAD-4-NH2 and XAD-4-N-S-Fe),aimed at deep-removal of fluoride ions,were synthesized by amination and sulfonation-amination-metal loading based on XAD-4 as matrix.The structure and properties of the resins were characterized and the adsorption characteristics of the resins were studied.The results showed that the adsorption capacity of XAD-4-NH2 could be larger than that of XAD-4-N-S-Fe in batch experiments.The pH-value could have little effect on the removal of fluorine ion for both resins.The adsorption process for fluoride ion with XAD-4-NH2 was physical adsorption while the adsorption with XAD-4-N-S-Fe was mainly chemical adsorption.The date of dynamic experiment of both resins followed the Pseudo-second-order equation.The breakthrough time of XAD-4-NH2 and XAD-4-N-S-Fe were 11h and 24h,respectively when setting 1mg/L of F-as the effluent concentration.The adsorption mechanism of fluoride ion onto XAD-4-NH2 was mainly electrostatic attraction interaction,while chemical adsorption played an important role for XAD-4-N-S-Fe.