鸡蛋壳对废水中亚甲基蓝的吸附性能研究

Adsorption Properties of the Methylene Blue by Eggshell

以废弃的鸡蛋壳为吸附剂,研究了其对亚甲基蓝的吸附作用,利用红外光谱对吸附前后的鸡蛋壳进行了表征。考察了溶液初始浓度、吸附温度、溶液p H、吸附时间对废水中亚甲基蓝吸附性能的影响。由此得出了鸡蛋壳对亚甲基蓝的最佳吸附条件。通过动力学模型、等温线方程对吸附实验数据进行了非线性拟合,结果表明,鸡蛋壳吸附亚甲基蓝等温线能较好较符合拟二级动力学模型,吸附过程为物理吸附;吸附过程较符合Freundlich方程,吸附过程为多层吸附;热力学参数分析结果显示该鸡蛋壳对亚甲基蓝吸附为自发、熵减小、放热过程。

In this study,eggshell was used to adsorb methylene blue（ MB）. The structure of eggshell before and after adsorption was analyzed by means of infrared spectrometry. The batch experiments were performed under variable conditions including contact time,initial concentration of MB,p H and temperature. The optimal condition of adsorbent for MB was obtained. At the same time,the adsorption isothermal cure and kinetic equation were simulated to illustrate the adsorption effect. Kinetic studied demonstrated that the adsorption process was found to follow pseudo- second- order kinetics model,indicating a physical adsorption of MB by the waste eggshell. The isotherm indicated that the adsorption process was according with the Freundlich model, suggesting that adsorption was a mult- layer adsorption. The thermodynamic parameters showed the nature of Pb（ II） sorption was an endothermic spontaneous and a negentropy,exothermal,sorption behavior.