Rapid Adsorption of Cationic Methylene Blue Dye onto Volcanic Ash‑metakaolin Based Geopolymers
Rapid Adsorption of Cationic Methylene Blue Dye onto Volcanic Ash‑metakaolin Based Geopolymers
复制标题
火山灰-偏高岭土基地质聚合物上阳离子亚甲基蓝染料的快速吸附
DOI：
10.1007/s12633-021-01637-9
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发表时间：
2022
期刊：
影响因子：
3.4
通讯作者：
Timko, Michael T.
中科院分区：
文献类型：
--
作者：
Shikuku, Victor O.;Tome, Sylvain;Hermann Dzoujo T.;Tompsett, Geoffrey A.;Timko, Michael T.
以火山灰（VA）和偏高岭土（MK）为原料，分别合成了MK含量为0、10、30和50%的4种地质聚合物吸附剂GP 0、GP 10、GP 30和GP 50。通过X射线荧光（XRF）、X射线衍射（XRD）、拉曼光谱和Brunauer-Emmett-Teller（BET）表面积分析对材料进行表征，揭示了前体的成功地质聚合和表面积随着MK含量的增加而增加。然后评价VA、MK和VA-MK地质聚合物从水性介质中去除阳离子亚甲基蓝（MB）染料的吸附性能。吸附能力是独立的组合物，在吸附剂合成提供灵活性。另一方面，VA-MK地质聚合物的吸附速率比前体材料大3-8倍。的平衡吸附数据进行了适当的解释，Freundlich模型，表示多层吸附到一个异质的吸附表面具有较高的Freundlich亲和常数（KF）的地质聚合物比VA。吸附动力学符合拟二级动力学规律，30 min内平均去除率达98%。MB的吸收是pH依赖性的，并通过静电化学吸附相互作用驱动。这些结果激发了对使用当地来源的地质聚合物进行水净化应用的进一步研究。
In this study, four geopolymer sorbents GP0, GP10, GP30 and GP50 were synthesized using volcanic ash (VA) and metakaolin (MK) blends as precursors with 0, 10, 30 and 50% MK content by mass, respectively. The materials were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), Raman spectroscopy, and Brunauer–Emmett–Teller (BET) surface area analyses, revealing successful geopolymerization of the precursors and increasing surface area with increasing MK content. The sorption performance of the VA, MK and VA-MK geopolymers was then evaluated for the removal of cationic methylene blue (MB) dye from aqueous media. Sorption capacity was independent of composition, providing flexibility in sorbent synthesis. Sorption rate, on the other hand, was 3–8 times greater for the VA-MK geopolymers than the precursor materials. The equilibrium adsorption data were suitably explained by the Freundlich model, denoting multilayer adsorption onto a heterogeneous adsorption surface with higher Freundlich affinity constant (KF) for geopolymers than VA. The adsorption kinetics obeyed the pseudo-second-order (PSO) kinetic law with an average of 98% removal efficiency in 30 min. MB uptake was pH-dependent and driven by electrostatic chemisorption interactions. These results motivate further studies on the use of locally sourced geopolymers for water purification applications.