A State-of-the-Art Review on Effectiveness of Geopolymer Technology Toward Dye Degradation, Heavy Metal Encapsulation and Its Future Prospects on Environmental Remediation

Geopolymers are an innovative class of environmentally friendly materials gaining significant attention in construction, materials science, and sustainable technology. As alternatives to traditional cement-based materials, geopolymers exhibit unique mechanical properties suitable for various construction applications, including use as construction materials, coating materials, and high-temperature-resistant materials. Notably, geopolymers can effectively adsorb heavy metals, dyes, and radioactive pollutants, offering substantial environmental benefits. This review paper explores the process and mechanism of geopolymerization, as well as the application of geopolymers in the treatment of contaminants. It details how aluminosilicate precursors contribute to the photocatalytic degradation of dyes, examining the role of different raw material sources, types of activators or additives used, and preparation methods. This paper highlights the effectiveness of geopolymers in dye degradation, providing insights into the underlying mechanisms. Additionally, the review delves into the interaction of geopolymers with heavy metals through mechanisms such as chemisorption, complexation, adsorption, ion exchange, intraparticle diffusion, and the solidification of heavy metals within the geopolymer matrix. This comprehensive analysis of existing research aids researchers in understanding the capabilities and limitations of geopolymer materials in environmental remediation. Beyond waste reduction, the review addresses the broader environmental impact of geopolymers, particularly their potential for reducing the carbon footprint compared to traditional cement. This aspect is crucial for evaluating the overall sustainability of geopolymers. Furthermore, the paper emphasizes the importance of life cycle durability assessments (LCA) to evaluate the ecological footprint of this eco-friendly concrete throughout its lifetime, from raw material to end-of-life disposal. LCA provides a complete perspective on the sustainability of geopolymers, guiding future research and applications in sustainable construction. By synthesizing current research on geopolymers, this review paper serves as a valuable resource for researchers in geopolymer technology, offering insights into future research directions and potential applications.