To further improve the removal ability of layered double hydroxide(LDH) for iodide(I^-) anions from wastewater, we prepared hierarchically porous Cu5Mg10Al5-LDH and used as a matrix for in suit growth of Cu/Cu2O on it...To further improve the removal ability of layered double hydroxide(LDH) for iodide(I^-) anions from wastewater, we prepared hierarchically porous Cu5Mg10Al5-LDH and used as a matrix for in suit growth of Cu/Cu2O on its surface, forming Cu/Cu2O-LDH, which was characterized and applied as an adsorbent.Results displayed high I^-saturation uptake capability(137.8 mg/g) of Cu/Cu2O-LDH compared with Cu5Mg10Al5-LDH(26.4 mg/g) even thermal activated LDH(76.1 mg/g).Thermodynamic analysis showed that the reaction between I^-anions and Cu/Cu2O-LDH is a spontaneous and exothermic.Uptake kinetics analysis exhibited that adsorption equilibrium can be reached after 265 min.Additionally, the adsorbent showed satisfactory selectivity in the presence of competitive anions(e.g., SO4^2-), and could achieve good adsorption performance in a wide pH range of 3–8.A cooperative adsorption mechanism was proposed on the basis of the following two aspects:(1) ion exchange between iodide and interlayer anions;(2) the adsorption performance of Cu, Cu(Ⅱ) and Cu2O for I^-.Meanwhile, the difference between the adsorption mechanism of Cu/Cu2O-LDH, Cu5Mg10Al5-LDH and Cu5Mg10Al5-CLDH adsorbents was also elaborated and verified.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11805101 and 11205089)the Jiangsu Engineering Technology Research Center of Environmental Cleaning Materials(No.KFK1504)the Environmental Protection Research Project of Jiangsu Province(No.JSZC-D2018-044).
文摘To further improve the removal ability of layered double hydroxide(LDH) for iodide(I^-) anions from wastewater, we prepared hierarchically porous Cu5Mg10Al5-LDH and used as a matrix for in suit growth of Cu/Cu2O on its surface, forming Cu/Cu2O-LDH, which was characterized and applied as an adsorbent.Results displayed high I^-saturation uptake capability(137.8 mg/g) of Cu/Cu2O-LDH compared with Cu5Mg10Al5-LDH(26.4 mg/g) even thermal activated LDH(76.1 mg/g).Thermodynamic analysis showed that the reaction between I^-anions and Cu/Cu2O-LDH is a spontaneous and exothermic.Uptake kinetics analysis exhibited that adsorption equilibrium can be reached after 265 min.Additionally, the adsorbent showed satisfactory selectivity in the presence of competitive anions(e.g., SO4^2-), and could achieve good adsorption performance in a wide pH range of 3–8.A cooperative adsorption mechanism was proposed on the basis of the following two aspects:(1) ion exchange between iodide and interlayer anions;(2) the adsorption performance of Cu, Cu(Ⅱ) and Cu2O for I^-.Meanwhile, the difference between the adsorption mechanism of Cu/Cu2O-LDH, Cu5Mg10Al5-LDH and Cu5Mg10Al5-CLDH adsorbents was also elaborated and verified.
