细菌纤维素对重金属离子的吸附机理研究

Adsorption mechanism of bacterial cellulose to heavy metal ions

以细菌纤维素(BC)为吸附剂,对重金属离子Cu2+,Pb2+和Cd2+的吸附等温线和吸附动力学特性进行了研究,并采用红外光谱分析法探讨了吸附作用机理。结果表明:BC对Cu2+,Pb2+和Cd2+吸附更好地符合Langmuir吸附等温方程和准二级反应动力学模型,说明吸附过程为单分子层吸附,化学吸附作用为主。粒子内扩散拟合曲线均不经过原点,证明粒子内扩散并不是唯一速率控制步骤。FT-IR分析表明吸附金属离子后的BC中—OH最大吸收位发生不同程度的蓝移,说明BC中部分—OH参与吸附,即与重金属离子之间发生反应,从而使—OH的数量减少。

To examine the possibility of metal adsorption by bacterial cellulose （BC）, the adsorption kinetics characteristics and adsorption isotherm to Cu^2＋, Ph^2＋ and Cd^2＋ were studied. FT-IR was applied to investigate the adsorption mechanism of metal ions by BC. The results show that adsorption process can be described by Langmuir model and second-order reaction kinetics. It indicates that the adsorption of BC obeys the formation of monolayer molecule sorption with the main action of chemical adsorption. Because the constants C obtained with a particles internal diffusion model is not zero, particles internal diffusion is not the only one controlling rate step. The FT-IR analysis shows that the maximum wavenumber of-OH on BC after adsorbed is shifted to blue range due to reducing the number of-OH.