Reusable Porous SiO2 for Methylene Blue Removal: A Study on Adsorption and Regeneration Cycles

• Published in: Water, air, and soil pollution air, and soil pollution, 2024-11, Vol.235 (11), p.715, Article 715
• Main Authors: Cisneros-Trejo, Samara J., Paraguay-Delgado, Francisco, Hernández-Hernández, Arturo, Pantoja-Espinoza, Juan C.
• Format: Article
• Language: English
• Subjects: Adsorption; Atmospheric Protection/Air Quality Control/Air Pollution; Chemical composition; Climate Change/Climate Change Impacts; Earth and Environmental Science; Environment; Gels; Hydrogeology; Methylene blue; Pollution; Porous silicon; Silica; Silicon dioxide; Soil Science & Conservation; Sol-gel processes; Structural stability; Synthesis; Thermal regeneration; Thermal stability; Water pollution; Water Quality/Water Pollution; Water treatment
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-024-07539-x

In response to the water contamination problem, this study presents a novel method to remove methylene blue (MB), a typical water pollutant, using synthesized porous silicon dioxide (SiO 2 ). The SiO 2 was synthesized via a cost-effective sol–gel method and characterized for its thermal stability, structural, textural, morphological properties, and elemental composition using techniques such as TGA, FT-IR, XRD, BET-BJH, SEM, TEM, and STEM-EDS. A unique aspect of this study is the evaluation of SiO 2 reusability in MB removal through multiple adsorption and thermal regeneration cycles, a critical factor for practical applications. The results demonstrated the successful synthesis of thermally stable, amorphous, porous SiO 2 with a surface area of 811 m 2 g −1 initially, reducing to 600 m 2 g −1 after the adsorption and regeneration cycles, indicating its stability and durability. The removal efficiency of MB was consistent across cycles, achieving 71.19 ± 0.94%, 75.55 ± 0.69%, and 73.49 ± 0.15% after 20 min, and the adsorption capacity at equilibrium was 3.73 ± 0.025, 4.08 ± 0.045, and 3.48 ± 0.021 mg MB g ads −1 during the first, second, and third cycles, respectively. These findings highlight the potential of the synthesized porous SiO 2 as a reusable and efficient adsorbent for MB removal in water treatment, contributing to the advancement of sustainable and effective solutions for water pollution.