Application of low-cost mesoporous geopolymer for dye waste removal

Environmental pollution causes a significant reduction in water quality. Sustainable development and industrial waste pollution are the supporting factors for the amount of water that is not suitable for consumption. Contaminants in wastewater that pollute water sources include phenolic compounds, substituted compounds, various types of pesticides, and dyes. This study focuses on developing geopolymers as a low-cost alternative adsorbent for adsorbing harmful dyes. Geopolymers can rapidly absorb dyes due to their supportive surface properties to absorb dyes. The porous structure is derived from alumino-silicate materials such as kaolin, metakaolin, dolomite, fly ash, and slag which have been activated with alkaline or alkaline silicate solution. Geopolymers are readily stored adsorbents. Geopolymers have shown good adsorption capacity of the dyes of Methylene blue, Rhodamine B, Congo Red, Methyl Orange, Methyl Violet. This study aims to provide an overview of the types of geopolymer forming materials, geopolymer characterization, application of geopolymers as dye adsorbents, and comparison with other adsorbents. The adsorption isotherm model and adsorption kinetics are also summarized in this overview.