Statistical Optimization and Desirability Function for Producing Nano Silica from Dune Sand by Sol–gel Method Towards Methylene Blue Dye Removal

• Published in: Journal of Inorganic and Organometallic Polymers and Materials
• Main Author: Hani A.; Meftah N.; Zeghoud L.; Sdiri A.; Jawad A.H.
• Format: Article
• Language: English
• Published: Springer 2023
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85151557246&doi=10.1007%2fs10904-023-02612-0&partnerID=40&md5=0f2a0a5d2f9ee73d9597fa2f79d7c7e6

This work aims to extract amorphous, high-purity silica nanoparticles (n-SiO2) from natural sand using the sol–gel method, a simple, economic, and environmentally friendly chemical process. The parametric optimization by Box–Behnken design was carried out to optimize the synthesis parameters (reaction temperature, reaction time, and SiO2/NaOH ratio). The as-produced silica was characterized by several analytical techniques. A maximum silica yield of 87.62% was achieved when the T = 495.3 °C, t = 2 h and SiO2/NaOH = 7.88. The XRF and EDX results affirmed the high purity of the synthesized silica at 98.4% SiO2. The XRD spectrum shows an amorphous structure of the as-produced silica. Furthermore, the extracted silica exhibited a high specific surface area of 632.7m2/g, an average pore diameter of 2.82 nm, and an average particle size of 9.48 nm. The applicability of the BBD-optimized n-silica as a low-cost adsorbent toward removing Methylene blue (MB) dye from the aqueous environment was investigated. The adsorption kinetic was in excellent accordance with a pseudo-second-order kinetic models and the Temkin isotherm model, with a maximum adsorption capacity of 209.23 mg/g at 55 °C. These findings demonstrate that sand is a promising precursor for producing highly pure mesoporous silica for removing cationic dyes from wastewater and other possible applications. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.