State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
J Hazard Mater. 2017 May 5;329:66-76. doi: 10.1016/j.jhazmat.2017.01.025. Epub 2017 Jan 16.
In this study, raw attapulgite (APT) and a novel adsorbent, struvite/attapulgite (MAP/APT) obtained from nutrient-rich wastewater treated by MgO modified APT, were applied as the absorbent for Cd(II) ion removal from aqueous solution. The two adsorbents were characterized by BET, SEM-EDS, XRD, FT-IR. Raw APT and MAP/APT separately presented the maximum Cd(II) adsorption capacities of 10.38mg/g and 121.14mg/g at pH of 5.45. The Cd(II) adsorption on raw APT and MAP/APT could be well fitted by Freundlich isotherm and Langmuir isotherm, respectively. Pseudo-second order equation was able to properly describe the kinetics of Cd(II) adsorption by raw APT and MAP/APT. The calculated thermodynamic parameters indicated that Cd(II) adsorption onto raw APT and MAP/APT were spontaneous and endothermic. An economic evaluation revealed that the treatment costs of the adsorption process by raw APT and MPA/APT were 0.013 $ per 1000mg Cd and 0.004 $ per 1000mg Cd, respectively.
在这项研究中，采用从富含营养物质的废水中用 MgO 改性的凹凸棒土（APT）处理得到的原始凹凸棒土（APT）和新型吸附剂鸟粪石/凹凸棒土（MAP/APT）作为从水溶液中去除 Cd(II)离子的吸附剂。通过 BET、SEM-EDS、XRD、FT-IR 对两种吸附剂进行了表征。在 pH 为 5.45 时，原始 APT 和 MAP/APT 分别呈现出最大的 10.38mg/g 和 121.14mg/g 的 Cd(II)吸附容量。原始 APT 和 MAP/APT 上的 Cd(II)吸附均能很好地符合 Freundlich 等温线和 Langmuir 等温线。拟二级方程能够很好地描述原始 APT 和 MAP/APT 上 Cd(II)吸附的动力学。计算得到的热力学参数表明，原始 APT 和 MAP/APT 上的 Cd(II)吸附是自发和吸热的。经济评估表明，原始 APT 和 MPA/APT 吸附过程的处理成本分别为每去除 1000mg Cd 为 0.013 美元和每去除 1000mg Cd 为 0.004 美元。
