竹炭微波改性及对4-硝基苯酚的吸附动力学研究

利用微波氯化锌法对竹炭进行改性,以提高其吸附性能.通过正交实验,优化改性工艺条件,并用改性竹炭对4-硝基苯酚的吸附动力学和机理进行探讨.结果表明,最佳工艺条件为:固液比为1∶2时,50%氯化锌溶液浸泡8 h,800 W微波功率辐照6 min,相对于未改性竹炭,其比表面积、孔容、对4-硝基苯酚的吸附量明显增大.用伪二级吸附速率方程拟合,相关系数r＞0.999,颗粒内扩散过程不是该吸附速率的控制步骤.改性竹炭对4-硝苯酚的吸附是一个吸热过程,吸附活化能为16.81 kJ·mol-1,以物理吸附为主.

Bamboo-carbon Modified with Microwave Irradiation for Adsorption Kinetics of 4-nitrophenol

Bamboo-carbon was modified with ZnCl2 by microwave radiation to enhance its adsorption capacity, the optimum technology was obtained through orthogonal test, and the kinetics and mechanism of adsorption of 4-Nitrophenol by modified bamboo-carbon were studied. The results showed that the optimum conditions were as follows: ratio of ZnCl2 solution to bamboo-carbon is 2.0 to 1.0, concentration of ZnCl2 solution50% and impregnating time 8 hours, microwave power 800 watts, radiation time 6 minutes. Compared with bamboo-carbon, the specific surface areas, total pore volume and the adsorption efficiency of 4-nitrophenol of modified bamboo-carbon were increased obviously. The adsorption processes follow a pseudo second-order kinetic rate equation and their linear correlation coefficients could be over 0.999. Intra-particle diffusion was not the rate-controlling step. The adsorption of 4-nitrophenol by modified bamboo-carbon, which was an endothermic process. has a small energy of activation, and was mainly a physical adsorption process.