Mo Huinan, Shan Huimei, Xu Yuqiao, Liao Haimin, Peng Sanxi
College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541004, China.
Collaborative Innovation Center of Water Pollution Control and Water Security in Karst Area, Guilin University of Technology, Guilin 541004, China.
Molecules. 2024 Aug 25;29(17):4021. doi: 10.3390/molecules29174021.
Antimony (Sb) is one of the most concerning toxic metals globally, making the study of methods for efficiently removing Sb(III) from water increasingly urgent. This study uses graphene oxide and chitosan as the matrix (GOCS), modifying them with FeCl and four MnO to form iron-manganese oxide (FM/GC) at a Fe/Mn molar ratio of 4:1. FM/GC quaternary composite microspheres are prepared, showing that FM/GC obtained from different MnO exhibits significant differences in the ability to remove Sb(III) from neutral solutions. The order of Sb(III) removal effectiveness is MnSO > KMnO > MnCl > MnO. The composite microspheres obtained by modifying GOCS with FeCl and MnSO are selected for further batch experiments and characterization tests to analyze the factors and mechanisms influencing Sb(III) removal. The results show that the adsorption capacity of Sb(III) decreases with increasing pH and solid-liquid ratio, and gradually increases with the initial concentration and reaction time. The Langmuir model fitting indicates that the maximum adsorption capacity of Sb(III) is 178.89 mg/g. The adsorption mechanism involves the oxidation of the Mn-O group, which converts Sb(III) in water into Sb(V). This is followed by ligand exchange and complex formation with O-H in FeO(OH) groups, and further interactions with C-OH, C-O, O-H, and other functional groups in GOCS.
锑（Sb）是全球最受关注的有毒金属之一，使得高效去除水中Sb（III）的方法研究变得越来越紧迫。本研究以氧化石墨烯和壳聚糖为基质（GOCS），用FeCl和四种MnO对其进行改性，以4:1的Fe/Mn摩尔比形成铁锰氧化物（FM/GC）。制备了FM/GC四元复合微球，结果表明，由不同MnO得到的FM/GC对中性溶液中Sb（III）的去除能力存在显著差异。Sb（III）去除效果的顺序为MnSO＞KMnO＞MnCl＞MnO。选择用FeCl和MnSO改性GOCS得到的复合微球进行进一步的批量实验和表征测试，以分析影响Sb（III）去除的因素和机制。结果表明，Sb（III）的吸附容量随pH值和固液比的增加而降低，随初始浓度和反应时间的增加而逐渐增加。Langmuir模型拟合表明，Sb（III）的最大吸附容量为178.89 mg/g。吸附机制包括Mn-O基团的氧化作用，将水中的Sb（III）转化为Sb（V）。随后是与FeO（OH）基团中的O-H进行配体交换和络合形成，以及与GOCS中的C-OH、C-O、O-H等官能团的进一步相互作用。
