皂化菠萝皮渣对重金属Zn^(2+)的吸附

Adsorption of Zn^(2+) by saponified pineapple peel

采用五因子二次回归正交旋转组合设计的方法对影响皂化菠萝皮渣吸附Zn2+的因子进行优化,得出在时间为1 h、加入量0.1 g、p H=9、温度20℃、浓度120 mg/L时,皂化菠萝皮渣有最大去除率YMax=99.12%。对比实验表明,皂化菠萝皮渣对Zn2+的吸附在低浓度时优于活性炭,纤维素在吸附中起主要作用。扫描电镜下菠萝皮渣表面显示粗糙和多褶皱的物理吸附特征,红外光谱显示皂化菠萝皮渣中OH、CO、C—O基团参与吸附作用。吸附等温线和吸附动力学模型显示皂化菠萝皮渣对Zn2+的吸附符合Freundlich等温式和二级动力学模型。吸附Zn2+后的皂化菠萝皮渣经过解吸附可以重复使用。

Experimental conditions for the adsorption of Zn2 +by the saponified pineapple peel were optimized using a five factors and quadratic rotation-orthogonal composite experimental design. Maximum adsorption rate( 99. 12%) was obtained when the amount of 0. 1 g was added to the solution( p H =9) and held at 20℃for 1 h.The saponified pineapple peel had better adsorption efficiency on Zn2 +at low concentration than activated carbon,and the cellulose fraction played a major role in the adsorption. The physical adsorption characteristics by scanning electron microscopy showed that the surface of saponified pineapple peel was rough and multi-folded. The groups of OH and and CO and C—O in the saponified pineapple peel played a role in the adsorption of Zn2 +which showed by infrared spectroscopy. According to the adsorption rate model and the adsorption isotherms,the adsorption of the saponified pineapple peel on Zn2 +was in accordance with Freundlich isotherm equation and two order kinetic model. The saponified pineapple peel after adsorbing Zn2 +can be used repeatedly by desorption.