【摘要】 为改善活性炭纤维(ACFs)表面的酸性基团,并提高其对水中重金属离子的去除效率,采用NaClO对ACFs进行氧化改性,研究了吸附时间和温度对水溶液中铜离子的去除影响,用准一级、准二级动力学模型和内扩散模型来研究铜离子在改性ACFs上的吸附动力学行为。结果表明:铜离子在改性ACFs上的吸附平衡可以在50min内达到,且升高温度可以增加铜离子的去除率。准二级动力学模型可以很好地描述铜离子在改性ACFs的吸附行为,其相关系数R~2>0.99.根据吸附热力学的分析可知其标准吸附焓变ΔH0>0,该过程是吸热反应;且活化状态函数值是20.48kJ/mol,表明了该过程是以物理吸附为主。用改性ACFs去除水溶液中铜离子的性能明显比未改性的ACFs高,其去除率从70.2%增加到94.5%.更多还原

【Abstract】 The surface of activated carbon fibers(ACFs)was modified by using sodium hypochlorite in present work to improve the acidic groups on the surface and the removal efficiency of heavy metal ions in water.The adsorption time and temperatures affecting the removal rate of copper(Ⅱ)were analyzed,and results indicate that adsorption equilibrium was obtained within50 minutes and the removal rate increased with increasing temperature.It can be concluded from the fitting results of pseudo-first-order and pseudo-second-order kinetic models that the pseudosecond-order kinetic model satisfactorily correlated the experimental data,with R2 larger than0.99.Fitting results of intraparticle diffusion model show that the adsorption process was controlled by liquid film diffusion and intra-particle diffusion.In addition,the thermodynamic data suggest that the adsorption process was endothermic and could occur spontaneously.The adsorption activation energy is 20.48 kJ/mol,revealing that it belong to physics adsorption.The removal of copper(Ⅱ)ions in water using modified ACFs is significantly higher than that using ACFs,showing an increase from 70.2%to 94.5%.更多还原