Li Kunquan, Wang Xiaohua
College of Engineering, Nanjing Agricultural University, Dianjiangtai Road N. 40, Nanjing 210031, China.
Bioresour Technol. 2009 Jun;100(11):2810-5. doi: 10.1016/j.biortech.2008.12.032. Epub 2009 Feb 8.
Low-cost activated carbon was prepared from Spartina alterniflora by phosphoric acid activation for the removal of Pb(II) from dilute aqueous solution. The effect of experimental parameters such as pH, initial concentration, contact time and temperature on the adsorption was studied. The obtained data were fitted with the Langmuir and Freundlich equations to describe the equilibrium isotherms. The kinetic data were fitted with the Lagergren-first-order, pseudo-second-order and Elovich models. It was found that pH played a major role in the adsorption process. The maximum adsorption capacity for Pb(II) on S. alterniflora activated carbon (SAAC) calculated from Langmuir isotherm was more than 99 mg g(-1). The optimum pH range for the removal of Pb(II) was 4.8-5.6. The Freundlich isotherm model was found to best describe the experimental data. The kinetic rates were best fitted to the pseudo-second-order model. Thermodynamic study showed the adsorption was a spontaneous exothermic process.
通过磷酸活化法以互花米草为原料制备低成本活性炭，用于从稀水溶液中去除Pb(II)。研究了pH值、初始浓度、接触时间和温度等实验参数对吸附的影响。将所得数据与朗缪尔方程和弗伦德利希方程拟合，以描述平衡等温线。动力学数据与 Lagergren 一级、准二级和埃洛维奇模型拟合。结果发现，pH值在吸附过程中起主要作用。根据朗缪尔等温线计算，互花米草活性炭（SAAC）对Pb(II)的最大吸附容量超过99 mg g(-1)。去除Pb(II)的最佳pH范围为4.8-5.6。发现弗伦德利希等温线模型最能描述实验数据。动力学速率最适合准二级模型。热力学研究表明，吸附是一个自发的放热过程。
