改性单宁的制备及吸附动力学

Preparation and Adsorption Kinetics of Modified Tannins

以单宁酸为原料,以甲醛和聚乙烯亚胺为交联剂,制备了改性单宁吸附材料。采用了红外光谱(FT-IR)以及X-射线衍射(XRD),对改性后的材料进行了表征,最后用原子吸收光谱测定了该材料对Cu^(2+)的吸附性能。实验结果证明,单宁酸在聚乙烯亚胺和甲醛的作用下成功交联。吸附性能的分析表明,改性单宁的吸附过程符合准二级动力学模型,吸附过程受化学反应控制,平衡时的吸附容量为171.527 mg·g^(-1)。

Using tannic acid as raw material and formaldehyde and polyethylenimine as cross-linking agents,modified tannin adsorbent was prepared.The FT-IR and X-ray diffraction(XRD)techniques were used to characterize the modified materials.Finally,the adsorption properties of Cu2+on the materials were determined by atomic absorption spectroscopy.The experimental results show that tannic acid is successfully cross-linked by the action of polyethyleneimine and formaldehyde.The analysis of adsorption performance shows that the adsorption process of modified tannins accords with the pseudo-second-order kinetics model.The adsorption process is controlled by chemical reaction and the adsorption capacity at equilibrium is 171.527 mg·g^-1.