Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
J Hazard Mater. 2015 Dec 30;300:847-854. doi: 10.1016/j.jhazmat.2015.08.020. Epub 2015 Aug 17.
The coexistence of cadmium ion (Cd(II)) and antimonate (Sb(V)) creates the need for their simultaneous removal. This study aims to investigate the effects of positively-charged Cd(II) on the removal of negative Sb(V) ions by Fe-Mn binary oxide (FMBO) and associated mechanisms. The maximum Sb(V) adsorption density (Qmax,Sb(V)) increased from 1.02 to 1.32 and 2.01 mmol/g in the presence of Cd(II) at 0.25 and 0.50 mmol/L. Cd(2+) exhibited a more significant positive effect than both calcium ion (Ca(2+)) and manganese ion (Mn(2+)). Cd(2+) showed higher affinity towards FMBO and increased its ζ-potential more significantly compared to Ca(2+) and Mn(2+). The simultaneous adsorption of Sb(V) and Cd(II) onto FMBO can be achieved over a wide initial pH (pHi) range from 2 to 9, and QSb(V) decreases whereas QCd(II) increases with elevated pHi. Their combined values, as expressed by QSb(V)+Cd(II), amount to about 2 mmol/g and vary slightly in the pHi range 4-9. FTIR and XPS spectra indicate the significant synergistic effect of Cd(II) on Sb(V) adsorption onto FMBO, and that little chemical valence transformation occurs. These results may be valuable for the treatment of wastewater with coexisting heavy metals such as Cd(II) and Sb(V).
镉离子 (Cd(II)) 和锑酸盐 (Sb(V)) 的共存需要同时去除。本研究旨在探讨带正电荷的 Cd(II) 对 Fe-Mn 二元氧化物 (FMBO) 去除带负电荷的 Sb(V) 离子的影响及其相关机制。在 0.25 和 0.50 mmol/L 的 Cd(II) 存在下，Sb(V) 的最大吸附密度 (Qmax,Sb(V)) 从 1.02 增加到 1.32 和 2.01 mmol/g。Cd(2+) 的正效应比钙离子 (Ca(2+)) 和锰离子 (Mn(2+)) 都更显著。与 Ca(2+) 和 Mn(2+) 相比，Cd(2+) 对 FMBO 具有更高的亲和力，并且更显著地增加了其 ζ-电位。FMBO 可以在很宽的初始 pH (pHi) 范围（2-9）内同时吸附 Sb(V) 和 Cd(II)，而 QSb(V) 随着 pH 值的升高而降低，而 QCd(II) 则升高。它们的组合值，以 QSb(V)+Cd(II) 表示，约为 2 mmol/g，并且在 pH 4-9 的范围内变化不大。FTIR 和 XPS 谱表明，Cd(II) 对 Sb(V) 在 FMBO 上吸附的协同作用显著，而且化学价态变化很小。这些结果对于处理含有共存重金属如 Cd(II) 和 Sb(V) 的废水可能具有重要意义。
