Department of Environmental Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.
School of Civil Engineering, Universiti Sains Malaysia, George Town, Penang, Malaysia.
Environ Sci Pollut Res Int. 2024 Sep;31(43):55577-55596. doi: 10.1007/s11356-024-34837-y. Epub 2024 Sep 6.
In this study, novel lamellar double hydroxide composites (LDH-MgAl and LDH-MgFe) were synthesized at different metal salt ratios (1:1 to 3:1) and fully characterized using various techniques such as XRD, FTIR, SEM, EDS, and TGA. The resulting LDHs demonstrated a high affinity for efficiently removing tetracycline (TC) antibiotic from water, particularly at a moderate molar ratio of 3:1. This ratio exhibited improved structural characteristics, resulting in better TC uptake from water. The improved performance was supported by the increased abundance of surface functional groups (OH, NO, CO, C-O-C, Fe-O, and Al-O-Al). The TGA analysis established the high stability of the LDHs when subjected to high temperatures. The kinetics of TC adsorption onto LDH fitted with the PSO (R = 0.935-0.994) and Avrami (R = 0.9528-0.9824) models, while the equilibrium data fitted the Liu and Langmuir isotherm models, with maximum monolayer adsorption capacities of 101.1 mg g and 70.83 mg g, respectively-significantly higher than many reported values in the literature. The positive values of ΔH and ΔS indicate an endothermic process, with TC removal mechanisms influenced by physical interactions, such as hydrogen bonding, electrostatic interaction, and π-cation with the surface functional groups of the LDH adsorbents. These results suggest that LDH-MgAl and LDH-MgFe are promising adsorbents for the removal of TC from water.
在这项研究中，我们在不同的金属盐比例（1:1 至 3:1）下合成了新型层状双氢氧化物复合材料（LDH-MgAl 和 LDH-MgFe），并使用 XRD、FTIR、SEM、EDS 和 TGA 等多种技术对其进行了充分的表征。结果表明，LDHs 对从水中高效去除四环素（TC）抗生素具有很高的亲和力，特别是在中等摩尔比为 3:1 时。这种比例表现出改进的结构特征，从而从水中更好地吸收 TC。增加表面官能团（OH、NO、CO、C-O-C、Fe-O 和 Al-O-Al）的丰度支持了这种改进的性能。TGA 分析表明 LDHs 在高温下具有高稳定性。TC 吸附到 LDH 上的动力学符合 PSO（R=0.935-0.994）和 Avrami（R=0.9528-0.9824）模型，而平衡数据符合 Liu 和 Langmuir 等温线模型，最大单层吸附容量分别为 101.1 mg g 和 70.83 mg g，明显高于文献中许多报道的值。正的ΔH 和ΔS 值表明这是一个吸热过程，TC 的去除机制受物理相互作用的影响，如氢键、静电相互作用和π-阳离子与 LDH 吸附剂表面官能团的相互作用。这些结果表明，LDH-MgAl 和 LDH-MgFe 是从水中去除 TC 的有前途的吸附剂。
