奶酪棒状氧化镁吸附水中重金属锰的效能与机理

以硫酸镁、碳酸氢铵为原料，在无表面活性剂条件下合成了棒状结构碱式碳酸镁前驱体，经高温热解得到多孔奶酪棒状氧化镁（C-MgO）。基于SEM、XRD、IR、TG表征技术分析了其表面形貌、物相组成、官能团组成等物化性能。并探究了C-MgO吸附废水中重金属锰的效能与机理。研究结果表明，C-MgO展示出5793mg/g超高的锰吸附能力，高于目前报道吸附材料。此外，动力学研究表明该材料能够在加入量仅为0.08g/L的条件下实现废水中锰的快速去除。吸附机理结果研究表明，C-MgO对锰的吸附过程主要吸附机理为氧化镁质子化、锰氢氧根配位、镁锰络合等，使活性氧化镁通过化学吸附转变为MgMn2O4。固定床动态吸附实验证明了C-MgO具有较好的应用前景。因此，该研究提供了一种便捷的前驱体法合成的奶酪棒状氧化镁合成技术，吸附材料能够实现锰废水的低成本、高效去除。

Adsorption performance and mechanism of manganese from wastewater by cheese-like MgO

The cheese rod-like magnesium oxide (C-MgO) was obtained by pyrolyzing basic magnesium carbonate precursor with rod shape synthesized from magnesium sulfate and ammonium bicarbonate in solution in the absence of surfactants. The surface morphology, phase composition, functional groups and other physical and chemical properties were analyzed using SEM, XRD, IR, TG characterization. The adsorption efficiency and mechanism of manganese by C-MgO were investigated from wastewater. The results show that C-MgO has a supremely high adsorption capacity of 5793 mg/g of manganese, which is higher than the reported adsorbents. In addition, kinetic results show that the C-MgO can achieve rapid removal of manganese from wastewater with low dosage of 0.08g/L. The results of adsorption mechanism study showed that the main adsorption mechanism of C-MgO for manganese is magnesium oxide protonation, manganese hydroxide coordination, magnesium manganese complexation, during which the MgO transformed into MgMn2O4 by chemisorption. The fixed bed adsorption experiment proves that C-MgO has a good potential application prospect. Therefore, this investigation provides a facile strategy for preparing high-performance cheese-like magnesium oxide, which can achieve low-cost and efficient removal of manganese from wastewater.