Ice-templated geopolymer beads for dye removal

Area of Science:

• Materials Science
• Environmental Engineering
• Chemical Engineering

Background:

• Wastewater treatment requires efficient and cost-effective adsorbents.
• Geopolymers present a promising alternative to traditional adsorbents.
• Developing standardized geopolymer structures is crucial for consistent performance.

Purpose of the Study:

• To develop and characterize novel geopolymer beads for wastewater treatment.
• To investigate the influence of ice-templating and binder content on bead properties.
• To evaluate the adsorption capacity of geopolymer beads for methylene blue removal.

Main Methods:

• Geopolymer beads were fabricated using an ice-templating method with liquid nitrogen.
• Polyethylene glycol 600 (PEG600) was used as a binder to standardize bead dimensions.
• Morphology, microstructure, and mechanical strength were assessed via compressive tests (ISO 18591).
• Adsorption tests were performed using methylene blue (MB) at various concentrations and contact times.

Main Results:

• Bead morphology and porosity, influenced by water content, significantly impacted adsorption efficiency.
• All tested geopolymer beads achieved an average MB removal efficiency of 98% after 24 hours.
• Optimized beads demonstrated rapid MB uptake, reaching 76% removal within 30 minutes.

Conclusions:

• Ice-templated geopolymer beads are effective and efficient adsorbents for wastewater treatment.
• The fabrication process, particularly water content, can be optimized to enhance adsorption performance.
• These low-cost geopolymer beads show significant potential for industrial application in pollutant removal.