Department of Chemistry, Faculty of Sciences, University of Douala, P.O. Box 24157, Douala, Cameroon.
Department of Physical Sciences, Kaimosi Friends University College, P.O. Box 385-50309, Kaimosi, Kenya.
J Environ Manage. 2022 Sep 15;318:115533. doi: 10.1016/j.jenvman.2022.115533. Epub 2022 Jul 6.
In this study, four pozzolan-based geopolymers GP, GP, GP, and GP were synthesized by alkaline activation and by substituting 0, 5, 10, and 20% of the precursor with sugarcane bagasse-derived biochar, respectively. The composites were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM/EDX), and Brunauer-Emmett-Teller (BET) surface area analyses, and applied to sequester methylene blue (MB) dye in an aqueous medium in batch mode. The alkaline activation of pozzolan-biochar blends resulted in the formation of poly (Ferro-sialate-siloxo)-biochar chains. The adsorption capacity increased with an increase in biochar content from 24.44 to 455.46 mg/g (18-fold) for GP and GP, respectively. The sorption kinetics of MB onto the composites followed pseudo-second-order kinetics while the equilibrium data were best described by the Sips isotherm model. The adsorption process was thermodynamically spontaneous, endothermic (ΔH = 14.32-32.20 kJ/mol), and physical. The amount of adsorbent required for the removal of 99% of a fixed amount of MB in different volumes of effluent was predicted. Cost-analysis indicates that the composites are efficient and cheaper eco-adsorbents than commercial activated carbon and are suitable alternative candidates for the removal of dyes from water.
在这项研究中，通过碱性激活，分别用甘蔗渣衍生生物炭替代前驱体的 0%、5%、10%和 20%，合成了四种基于火山灰的地质聚合物 GP、GP、GP 和 GP。通过 X 射线荧光（XRF）、X 射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM/EDX）和 Brunauer-Emmett-Teller（BET）表面积分析对复合材料进行了表征，并应用于在批量模式下将亚甲基蓝（MB）染料在水介质中固定。火山灰-生物炭混合物的碱性激活导致聚（亚铁-硅铝酸盐-硅氧烷）-生物炭链的形成。吸附容量随着生物炭含量的增加而增加，对于 GP 和 GP，分别从 24.44 增加到 455.46 mg/g（18 倍）。MB 吸附到复合材料上的吸附动力学符合准二级动力学模型，而平衡数据最好由 Sips 等温线模型描述。吸附过程是自发的、吸热的（ΔH = 14.32-32.20 kJ/mol）和物理的。预测了不同体积废水中固定量 MB 的去除所需的吸附剂用量。成本分析表明，与商业活性炭相比，这些复合材料是高效且更便宜的生态吸附剂，是从水中去除染料的合适替代候选物。
