Impact of Washing On Performance and Characteristics of Clay-Based Geopolymer Adsorbent

Abstract

The steep rise in human population and their exploitation of precious natural resources such as water have degraded the quality of ground and surface water over the years, and this is a matter of great concern. Dye pollution is a critical problem affecting water quality and aquatic ecosystems worldwide. Water treatment methods, such as clay-based adsorbents, have garnered significant attention due to their abundance, ready availability, simple synthesis processes, and potential for largescale production. This research investigates clay-based geopolymer adsorbents for removing cationic dyes from aqueous systems, focusing on the significance of the washing process on the properties and performance of the adsorbent. The adsorbents were prepared using sodium metasilicate and sodium hydroxide as alkali activators. The prepared adsorbents are characterized using X-ray diffraction, Brunauer–Emmett–Teller analysis, Fourier-transform infrared spectrometry, Raman spectroscopy, Field emission scanning electron microscopy, energy dispersive X-ray analysis, and zeta potential to understand their underlying science. The samples were washed and compared to evaluate the effects of washing on their properties and adsorption performance. A batch adsorption study was conducted on the prepared adsorbent samples using UV-visible spectroscopy to evaluate their dye removal efficiency. Methylene Blue, Crystal Violet, Rhodamine B, and Methyl Orange dyes were used as pollutants in the adsorption study.