Green-Synthesized Geopolymer from Acacia Extract and Coal Fly Ash for Sustainable Dye Degradation in Wastewater
DOI:
https://doi.org/10.55544/jrasb.5.3.11Keywords:
Green synthesis, Acacia extract, coal fly ash, geopolymer composite, photocatalysis, methylene blue, wastewater treatment, dye degradation, environmental remediationAbstract
The continuous discharge of dye-based industrial effluents into aquatic environments has become a serious ecological concern due to their toxicity, persistence, and adverse effects on human health and biodiversity. In the present work, a sustainable, eco-friendly geopolymer composite was synthesized via a green synthesis approach using coal fly ash and Acacia extract to efficiently remove methylene blue (MB) dye from wastewater. Coal fly ash, an industrial by-product rich in aluminosilicates, was alkali-activated with sodium hydroxide and sodium silicate solutions in order to create a geopolymer matrix. Acacia extract was used as a natural source of bioactive compounds that enhanced the surface functionality of the composite. The synthesized material was characterized using Fourier Transform Infrared Spectroscopy (FTIR), UV-Vis Spectroscopy, and Scanning Electron Microscopy (SEM) to investigate its structural, morphological, and elemental properties. FTIR analysis confirmed the formation of a geopolymer aluminosilicate network via characteristic Si-O-Si and Si-O-Al stretching vibrations, while SEM micrographs revealed a highly porous, interconnected surface morphology helpful to adsorption and photocatalytic reactions. UV–Visible spectroscopic studies showed a significant decrease in the characteristic absorption peak of methylene blue after treatment, indicating efficient dye degradation. Photocatalytic experiments demonstrated that the dye removal efficiency gradually increased with contact time, reaching about 78% after 120 min of visible-light irradiation. The pseudo-first-order kinetics of the degradation process indicate efficient interaction between the dye molecules and the active sites of the geopolymer composite.
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