Three types of ZnAl-rare metal ternary LDHs with M∶Al=1∶20(M=La,Zr,or Ce)were synthesized by co-precipitation,and their crystal structure,micro-morphology,and elemental composition were characterized.The adsorp-tion experiments were carried out to compare their performance in phosphate removal.The mechanisms of phosphate re-moval and the reasons for the differences in their adsorption capacities were analysed in depth.The results indicated that(a)all three LDHs were successfully synthesized;(b)their phosphate adsorption capacities were in the order of La-LDHs＞Zr-LDHs＞Ce-LDHs;(c)the phosphate adsorption was primarily chemical,involving electrostatic interac-tions,anion-metal coordination,and interlayer anion exchange,and their adsorption capacities were significantly inhibited by CO32-;(d)the superior phosphate removal performance of La-LDHs compared to the other two types of LDHs was mainly attributed to the larger ionic radius,more extended d orbitals of lanthanum ions and the rougher adsorbent surface.
NETL
NSTL
万方数据
