Selective removal of heavy metal ions in aqueous solutions by sulfide-selector intercalated layered double hydroxide adsorbent

Jing Wang¹，Liang Zhang¹，Tianshu Zhang¹，Ting Du¹，Tao Li²，Tianli Yue¹，Zhonghong Li¹，Jianlong Wang¹

1. College of Food Science and Engineering, Northwest A&F University2. Shaanxi Institute for Food and Drug Control

摘 要：Remaining largely under-appreciated,a majority of metal ion sorbents are limited in their target selectivity.In this work,a 3 D sulfide intercalated NiFe-layered double hydroxide（NFL-S）hierarchical sorbent has been synthesized for selective heavy metal removal.The intercalation of sulfurated groups in the interlayer of the layered double hydroxide（LDH）nanosheets endows NFL-S as a selective heavy metal ion filter;the selectivity of NFL-S for heavy metals is in the order of Pb²⁺>Cu²⁺≥Zn²⁺>Cd²⁺>Mn²⁺,and NFL-S has high kd values for Pb²⁺（～10⁶ mL/g）and Cu²⁺（～10⁵ mL/g）.Scanning electron microscopy,X-ray photoelectron spectroscopy and powder X-ray diffraction were used to analyze the composition of the as-prepared nanoadsorbent.The selective adsorption behavior was systematically studied using batch experiments,and the performance was evaluated through kinetic and isotherm studies.Moreover,the adsorption mechanism of heavy metals by NFL-S through surface complexation was also investigated,which shows great potential for water decontamination.

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