Ultrasonic-assisted synthesis of SiO2 nanoparticles and SiO2/chitosan/Fe nanocomposite and their application for vanadium adsorption from aqueous solution

The husk of brown rice, as a source of silica, was applied to synthesize natural SiO2 nanoparticles via sonochemical method. SiO2/CH/Fe nanocomposite was synthesized from SiO2, chitosan (prepared from shrimp shells via sonochemical method), and iron functional groups and detected using BET, EDX-SEM, and FTIR techniques. These natural-based nanostructures (SiO2 and SiO2/CH/Fe) have been applied for vanadium adsorption. The influences of initial pH, initial concentration, and adsorption time were studied via a batch process. The analysis of the kinetics data indicated that the chemical adsorption is predominant. The analysis of the equilibrium data indicated the single layer and exothermic adsorption process. The mono-layer adsorption capacity of SiO2/CH/Fe was 199.540 mg g(-1). The performance of SiO2/CH/Fe in a continuous column system was investigated in four adsorption and desorption cycles. Results showed that SiO2/CH/Fe nanocomposite synthesized with the sonochemical method is a candidate with high adsorption ability for use as an industrial adsorbent.

Automated summary

Natural SiO2 nanoparticles were synthesized from brown rice husk via sonochemical method and used for vanadium adsorption. SiO2/CH/Fe nanocomposite showed high adsorption capacity and predominance of chemical adsorption, with a mono-layer adsorption capacity of 199.540 mg g(-1). Results indicated a single layer, exothermic adsorption process, making it a promising industrial adsorbent.