【摘要】 探讨了初始浓度、接触时间、pH、离子强度等因素对针铁矿对去除水溶液中Cd（Ⅱ）的影响。利用X射线粉末衍射仪（XRD）对针铁矿进行表征,并通过批量实验研究了针铁矿对Cd（Ⅱ）吸附动力学和等温吸附机理。结果表明:针铁矿比表面积为82. 36 m²/g;准二级动力学和Langmuir等温吸附适用于针铁矿对Cd（Ⅱ）的吸附,相关系数分别为0. 9535和0. 9915;当25℃、pH为5时,用Langmuir等温线计算得到其最大吸附量为35. 29 mg/g;针铁矿吸附Cd（Ⅱ）能力随pH增大而增大;随着CaCl₂的浓度增大,针铁矿对Cd（Ⅱ）的吸附量减小,随着MgCl₂的浓度增大,针铁矿对Cd（Ⅱ）的吸附量先减小后上升,总体有抑制作用。更多还原

【Abstract】 The effect of initial aqueous concentration,contact time,p H and ionic strength on Cd（ Ⅱ） removal by goethite from aqueous solution were studied. Goethite was characterized by X-ray powder diffraction（ XRD）. The goethite surface area was determined to be 82. 36 m²/g. Batch experiments were carried out to determine the adsorption kinetics and isothermal mechanism of Cd（ Ⅱ） by goethite. Pseudo-second kinetic equation and Langmuir isotherm were found to fit the experimental data well（ r = 0. 9535 and 0. 9915,respectively）. The maximum adsorption capacity（ Q_m） calculated from Langmuir isotherm was found to be 35. 29 mg/g for Cd（ Ⅱ） with p H 5. 0 and 25 ℃. The adsorption process was found to be dependent with p H value. The adsorption capacity of Cd（ Ⅱ） increased with the increase of aqueous p H. In CaCl₂ and MgCl₂ solutions,Cd（ Ⅱ）adsorption decreased with increasing ionic strength. With the increase of CaCl₂ concentration,the adsorptive capacity of goethite to Cd（ Ⅱ） decreased. With the increase of MgCl₂ concentration,the adsorptive capacity of goethite to Cd（ Ⅱ）decreased at first,then increased,which had an inhibitory effect generally.更多还原