Department of Environmental Health, Faculty of Health, Hormozgan University of Medical Sciences, Bandar Abbas, Iran.
Department of Chemistry, Isfahan University of Technology, Isfahan, 84156-83111, Iran.
Environ Sci Pollut Res Int. 2018 Dec;25(36):36267-36277. doi: 10.1007/s11356-018-3584-8. Epub 2018 Oct 27.
Recently, a considerable attention has been paid on the preparation of layered double hydroxide (LDH) as a green adsorbent. This research presents a study on nickel and lead removal by Ca/Fe layered double hydroxides intercalate with citrate anions (Ca-Fe/LDH-Cit) which was successfully prepared through the co-precipitation and hydrothermal method. The as-synthesized Ca-Fe/LDH-Cit was characterized by various techniques including FT-IR, XRD, TGA, FE-SEM, and TEM techniques. The maximum uptake capacities of Ca-Fe/LDH-Cit were 2.26 mg/g for Ni(II) and 61.73 mg/g for Pb(II) inferred from the Langmuir model at the contact time of 30 min and pH of 7. Based on the results, the adsorption and kinetic isotherms were in good agreement with the Langmuir model and the pseudo-second-order equation, respectively. The results suggested that the composite adsorbent has the good ability to remove the Ni and Pb ions from aqueous solutions. The results reveal that the composite adsorbent can be considered as a high-capacity absorbent for Ni(II) and Pb(II) removal and also as a potential candidate for practical applications.
最近，人们对层状双氢氧化物 (LDH) 的制备作为一种绿色吸附剂引起了相当大的关注。本研究通过共沉淀和水热法成功制备了柠檬酸盐插层的钙铁层状双氢氧化物 (Ca-Fe/LDH-Cit)，并对其进行了镍和铅去除的研究。通过傅里叶变换红外光谱 (FT-IR)、X 射线衍射 (XRD)、热重分析 (TGA)、场发射扫描电子显微镜 (FE-SEM) 和透射电子显微镜 (TEM) 等多种技术对合成的 Ca-Fe/LDH-Cit 进行了表征。在 30 分钟接触时间和 pH 值为 7 的条件下，通过 Langmuir 模型推断出 Ca-Fe/LDH-Cit 的最大镍(II)和铅(II)吸附容量分别为 2.26 mg/g 和 61.73 mg/g。根据结果，吸附和动力学等温线分别与 Langmuir 模型和拟二级方程非常吻合。结果表明，该复合吸附剂具有从水溶液中去除 Ni 和 Pb 离子的良好能力。结果表明，该复合吸附剂可以被认为是一种用于去除 Ni(II)和 Pb(II)的高容量吸附剂，也是实际应用的潜在候选材料。
