Experimental investigation, kinetics and statistical modeling of methylene blue removal onto Clay@Fe3O4: Batch, fixed bed column adsorption and photo-Fenton degradation studies

Abstract

This study explores the use of muscovite mica combined with Fe3O4 nanoparticles to create a low-cost bio-composite. The composite was analyzed using XRD, pHPZC, FTIR, SEM, EDX, XRF, and BET. The investigation of adsorption parameters unveiled an adsorption efficacy of 97 % after 30 min with a ratio of 1 g/L. The experimental data aligned well with the pseudo-second-order equation and Temkin model, indicating a maximum adsorption capacity of 51.17 mg/g. Fixed-bed column studies demonstrated decreased efficiency with increased initial concentration, flow rate, and bed depth, with optimal performance at pH=8 and accurate representation by the Thomas model. The maximum capacity is achieved 34.69 mg/g when the bed depth is 0.5 cm, the flow rate is 2.5 mL/min, and the inlet concentration is 50 mg/L. The composite's degradation efficacy was evaluated under sunlight-activated photocatalysis, achieving over 95% degradation of MB within 90 minutes using 3 mL H2O2, an initial MB concentration of 40 mg/L, and only a catalyst quantity of 0.25 g/L. Degradation data were well-fitted by the first-order kinetic model. The study highlights the remarkable efficiency and swiftness of the degradation process compared to adsorption.

Keywords

• Fe3O4@Mus
• Bioadsorbent
• Biocatalyst
• Photo-Fenton
• Mechanism