Sustainable slag-based geopolymers incorporating styrofoam and Moringa leaves ash for mechanical enhancement and crystal violet adsorption

Abstract

Abstract Synthetic dye contamination poses a significant threat to water resources, necessitating the development of efficient removal technologies. This study introduces a novel organic-inorganic modified geopolymer for effective Crystal violet (CV) dye extraction from aqueous solutions. Additionally, it addresses waste management challenges by incorporating industrial (Slag, Styrofoam) and agricultural (Moringa leaves ash) waste into geopolymer cement. Slag-based geopolymer composites were synthesized with varying concentrations (1, 3, and 6 wt%) of Styrofoam (SSF1, SSF3, SSF6) and moringa leaves ash (SMA1, SMA3, SMA6). The mechanical properties of these composites were assessed over a curing period of up to 180 days in 100% humidity. While the control geopolymer sample (S) demonstrated superior compressive strength of 58.9 MPa after 180 days of curing, the modified geopolymer composites exhibited notable mechanical stability, with SSF1 and SMA1 achieving strengths of 52.8 MPa and 47.5 MPa, respectively. Furthermore, the adsorption performance of the modified geopolymer composites toward CV was evaluated as an additional environmental application. Notably, all modified geopolymers surpassed the control in CV removal, with SSF6 exhibiting an outstanding adsorption capacity of 434.78 mg/g. These findings demonstrate the potential of modified geopolymer composites as a promising, sustainable, and high-performance material for wastewater treatment applications.