Researchers have developed innovative catalysts derived from rice husk ash to effectively degrade harmful acid dyes, significantly addressing environmental pollution. This study presents mesoporous silica (SBA-16) and reduced graphene oxide (rGO) as promising substrates for Fe3O4 nanoparticles aimed at the degradation of acid blue 40 dye (AB40) through enhanced Fenton catalytic processes.
The widespread use of synthetic dyes, particularly AB40, poses significant environmental challenges due to their toxicity and persistence. Traditional wastewater treatment methods often fall short of effectively removing these contaminants from effluents. This study, conducted by N. Fathy, K. Abas, A. Attia, and M. S., explores the potential of Fenton-like reactions, which utilize iron-based catalysts for efficient dye degradation.
The catalysts were created by co-precipitating Fe3O4 nanoparticles on SBA-16 and rGO substrates, utilizing rice husk ash, making the approach not only effective but also economically viable. The resulting catalysts were characterized using advanced techniques such as field emission-scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD).
Key findings revealed the adsorption of AB40 dye fitting the Langmuir model, with maximum adsorption capacities reaching 169.2 mg/g for Fe3O4, 21.1 mg/g for Fe3O4/SBA-16, and 16.6 mg/g for Fe3O4/rGO. Adjustments to experimental conditions, including the initial dye concentration, pH of the solution, and the amount of hydrogen peroxide (H2O2) used, greatly influenced the decolorization efficiency. Optimal conditions were established, including using 1 g/L of catalyst at pH 3, where full decolorization of AB40 was achieved within 60 minutes at 35 °C.
At 25 °C and pH 3, the prepared Fe3O4 nanoparticles demonstrated superior Fenton activity. Notably, both SBA-16 and rGO significantly enhanced catalytic performance when the temperature exceeded 25 °C, indicating their synergistic effects on increasing hydroxyl radicals’ production. Remarkably, the regeneration tests of these Fenton-like catalysts showed over 95% stability, with minimal loss of activity even after four cycles of AB40 degradation.
The research offers important insights and solutions to tackle the environmental hazards presented by synthetic dyes and reinforces the viability of utilizing waste materials, such as rice husk ash, to create effective wastewater treatment technologies. The findings suggest promising avenues for future research and application of these cheap yet efficient catalysts at larger scales.
"The adsorption of AB40 dye followed the Langmuir model, with maximum adsorption capacities of 169.2, 21.1, and 16.6 mg/g for Fe3O4, for Fe3O4/SBA-16 and Fe3O4/rGO, respectively," wrote the authors of the article. The success of this innovative approach reinforces the potential of using sustainable materials for addressing pressing environmental challenges.
Overall, this research highlights the significant potential of these magnetite-based catalysts as Fenton-like reagents for the degradation of hazardous dye pollutants, marking substantial progress toward sustainable environmental remediation techniques.