摘要
以磷酸二氢铵为催化剂通过干法混合、干法反应工艺将玉米淀粉与柠檬酸反应制备出水不溶的柠檬酸淀粉酯,并将其用作Pb(Ⅱ)的吸附分离材料.研究了吸附剂酯基含量、吸附时间、温度、平衡Pb(Ⅱ)离子浓度、p H值等因素对柠檬酸淀粉酯吸附Pb(Ⅱ)的影响.结果表明,柠檬酸淀粉酯能有效除去溶液中的Pb(Ⅱ).柠檬酸淀粉酯对Pb(Ⅱ)的吸附速度很快,60 min便可以达到平衡,吸附动力学数据遵循假定一级动力学方程;柠檬酸淀粉酯对Pb(Ⅱ)的吸附是靠表面的羧基与Pb(Ⅱ)的作用完成的,吸附平衡资料很好的遵循了Sips等温吸附模型,由Sips参数得出最大吸附量为1.15 mmol·g-1.吸附热力学研究结果表明吸附过程是放热且自发发生的.p H值在1~7变化时柠檬酸淀粉酯对Pb(Ⅱ)的吸附量随p H值增大而升高.
Starch citrates were prepared via dry mixing and dry reaction process by using NH4H2 PO4 as catalyst and used to remove Pb （II） from aqueous solution. The effects of ester content of the adsorbent, adsorption time, temperature, Pb （II） ion concentration,and p H value on adsorption process were thoroughly investigated. The results show that the starch citrate can effectively remove P b （II） from solution. The results reveal that 60 min of adsorption time is sufficient for reaching the adsorption equilibrium and the pseudo-first-order kinetic model provides a better correlation of the experimental data in comparison with the pseudo-second-order m o d-el. The adsorption of Pb （II） on starch citrates depends on the active carboxyl groups of the adsorbent. The ad-sorption equilibrium data correlates well with the Sips isotherm model with amaximum adsorption capacity of 1.15 mmol ？ g-1. The adsorption of Pb （II） on C S P is exothermic in nature. The adsorption capacity increases with the pH increases from 1.0 to 7. 0.
出处
《鲁东大学学报（自然科学版）》
2017年第4期334-339,共6页
Journal of Ludong University:Natural Science Edition
基金
国家自然科学基金(21206066)
