Physical, Mechanical and Microstructure Properties of Metakaolin based Porous Alkali Activated Materials as an Adsorbent for Cu(II) Ion Removal

This study investigates the physical, mechanical, and microstructure properties of metakaolin-based porous alkali activated materials (AAM) at different surfactant concentrations as an adsorbent for Cu(II) ion removal. The AAM were synthesized using metakaolin as a precursor and alkali activators. Different surfactant contents ranging from 1 wt.% to 5 wt.% were incorporated into the AAM to enhance their adsorption capacity. The physical properties of the AAM were evaluated by determining their porosity, water absorption and density. The results showed that adding surfactant increased the AAM porosity, leading to higher water absorption. The highest porosity was observed at 3 wt.% surfactant content, indicating the optimal surfactant concentration for promoting a porous structure. The mechanical properties of the AAM were assessed through compressive strength tests. The microstructure analysis using scanning electron microscopy revealed that the AAM exhibited different microstructures depending on the surfactant content. The adsorption capacity and removal efficiency of the AAM for Cu(II) ion removal were determined. With a maximum adsorption capacity of 64.78 mg/g, the porous AAM could adsorb a significant quantity of Cu(II) ions. The outstanding removal efficiency of 97.17% showed the AAM maximum efficiency in removing Cu(II) ions from the solution at an adsorption condition of 25℃, pH 5, an initial concentration at 100 ppm and 60 minutes contact time.