丝瓜络的化学改性及其对金属离子的吸附

CHEMICAL MODIFICATION OF LUFFA SPONGE AND ITS ADSORPTION CHARACTERISTIC FOR METAL IONS

在乙醇/水混合介质中,通过微波辐射,得到预处理的丝瓜络纤维,SEM观测显示,预处理后其表面结构发生较大变化;TGA测定碱处理前后丝瓜络各成分的热降解,预处理后的丝瓜络的热性能没有明显变化。一氯乙酸对其进行化学改性,得到一种具有较强吸附能力的丝瓜络大孔树脂。电导率法研究表明,在一定浓度范围内,丝瓜络对Fe3+、Zn2+吸附动力学不符合Boyd方程,即吸附不是由液膜扩散控制。对Fe3+与Zn2+吸附符合Langmiur吸附等温式,其饱和吸附量分别为27.4mg·g-1和36.6mg·g-1。讨论了pH值对Zn2+的平衡吸附量的影响。

Alkali pretreated Luffa Sponge was gained by 30% NaOH aqueous with microwave radiation in ethanol/water mixture medium. Obvious change of its surface structure before and after pretreatment was observed by Scan Electron Microscope （SEM）.The decomposition of Luffa Sponge was determined by TGA,the heat-resistant property have no obvious change before and after pretreatment. The luffa Sponge was modified by monochloroacetic acid,a macroporous Luffa Sponge with good adsorptivity was gained.The adsorption behavior was studied by specific conductance,it is concluded that in the proper concentration range,the adsorption dynamics of Fe^3＋,Zn^2＋ didnot conform to Boyd equation well i,e.,the adsorption was not dominated by film diffusion.The Langmuir isotherm model best fit the equilibrium isotherm data.The maximum number of milli-gram of Fe^2＋ and Zn^2＋ adsorbed per gram of Luffa Sponge were 27.4 mg.g^-1 and 36.6 mg·g^-1 respectively.The effect ofpH on adsorption capacity of zinc ion was also discussed.