College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, PR China.
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, PR China.
Ecotoxicol Environ Saf. 2020 Apr 1;192:110326. doi: 10.1016/j.ecoenv.2020.110326. Epub 2020 Feb 15.
Adsorption represents an attractive mean to remediate polluted water. Unfortunately, the surface positive charges, low surface area and complicated separation procedures inhibit the usability of poly (m-phenylenediamine) (PmPD) as an adsorbent for heavy metal removing. To overcome these drawbacks, a magnetic MnO@FeO/PmPD core-shell adsorbent was designed to remove heavy metals from water. The MnO shell, came from the redox reaction between KMnO and PmPD, increased the surface area and changed the surface electronegativity. MnO@FeO/PmPD could be easily separated from water. It showed a significant increase in heavy metals removal efficiency, with maximum capacities of 438.6 mg/g for Pb(II) and 121.5 mg/g for Cd(II), respectively. The affinity between heavy metals and MnO@FeO/PmPD were mainly due to electrostatic attraction, ion exchanges and coordinated interaction. Density functional theory (DFT) calculations further confirmed that Pb and Cd were bonded with O atoms. The calculated adsorption energy indicated that the (111) MnO facet presented stronger adsorption affinity toward Pb(II) than Cd(II). Additionally, FM150 (150 mg) could regenerate 22 L Pb(II) wastewater upon single passage through the filterable column with a flux of 20 mL/min. Thus, the present work demonstrates the promising potential of using MnO@FeO/PmPD for efficiently removing heavy metals from wastewater.
吸附是一种很有吸引力的修复受污染水的方法。不幸的是，表面正电荷、低比表面积和复杂的分离程序限制了聚间苯二胺（PmPD）作为重金属去除吸附剂的可用性。为了克服这些缺点，设计了一种磁性 MnO@FeO/PmPD 核壳吸附剂，用于从水中去除重金属。MnO 壳层来源于 KMnO 和 PmPD 之间的氧化还原反应，增加了比表面积并改变了表面电负性。MnO@FeO/PmPD 可以很容易地从水中分离出来。它对重金属的去除效率显著提高，对 Pb(II) 的最大容量为 438.6mg/g，对 Cd(II) 的最大容量为 121.5mg/g。重金属与 MnO@FeO/PmPD 之间的亲和力主要归因于静电吸引、离子交换和配位相互作用。密度泛函理论（DFT）计算进一步证实 Pb 和 Cd 与 O 原子键合。计算的吸附能表明，(111)MnO 面对于 Pb(II)的吸附亲和力强于 Cd(II)。此外，FM150（150mg）可以在通量为 20mL/min 通过可过滤柱单次过滤 22L Pb(II)废水，从而再生。因此，本工作表明 MnO@FeO/PmPD 具有从废水中有效去除重金属的潜在应用前景。
