法桐树叶衍生生物质炭吸附含镍废水研究

Adsorption of Nickel-containing Wastewater by Biochar Derived from Platanus orientalis Leaves

以法桐树叶为原材料制备KOH改性的生物质炭吸附剂,对其表面性质进行表征,并研究其对含Ni(Ⅱ)废水的吸附性能。通过扫描电镜、比表面积分析仪及傅里叶红外光谱仪对制备的生物质炭表征分析证明,生物质炭呈现以微孔为主的多孔结构,比表面积为1733.01 m2/g,表面存在一定量的羟基、羧基等酸性表面官能团,有利于对Ni(Ⅱ)的吸附。25℃下,生物质炭对Ni(Ⅱ)的饱和吸附量为12.35 mg/g。通过对吸附实验数据拟合可知,其吸附行为符合准二级动力学模型,等温吸附过程符合Langmuir模型。生物质炭对Ni(Ⅱ)的吸附主要表现为单分子层化学吸附,同时伴有自发的吸热反应。

Biochar modified by KOH was prepared from the Platanus orientalis leaves.The surface properties of Biochar were characterized and its adsorption capacity for Ni(Ⅱ)in waste was studied.The results characterizd by scanning electron microscopy,specific surface area analyzer and Fourier transform infrared spectroscopy showed that the fabricated Biochar had porous structure dominated by micropores,and the specific surface area was 1733.01 m2/g.There are some acidic surface functional groups such as hydroxyl group and carboxyl group on the biochar surface,which is beneficial to the adsorption of Ni(Ⅱ).The saturated adsorption of biochar on Ni(Ⅱ)was 12.35 mg/g at 25℃.According to the fitting of the experimental data,the adsorption behavior is in accordance with the quasi second-order kinetic model,and the isothermal adsorption process is in accordance with the Langmuir model.The adsorption of Ni(Ⅱ)by biochar is mainly characterized by monolayer chemical adsorption;accompanied by spontaneous endothermic reaction.