In a recent study published in ACS Omega , Gladston L. dos Santos, Rebeca E. S. Barros, Yslaine A. de Almeida, Katlin I. B. Eguiluz, Giancarlo R. Salazar-Banda, and Iara F. Gimenez explored a highly efficient method for degrading methylene blue (MB) dye in aqueous solutions using biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More derived from bacterial cellulose (BC-derived biochar) as a catalytic support in an electrochemically assisted Fenton process. This innovative approach offers a promising solution to the significant environmental pollution caused by the textile industry, particularly from synthetic dyes like methylene blue, which pose serious health risks.

Traditional methods for dye removal, such as adsorption and bioremediation, often fall short in comprehensive degradation. Advanced oxidation processes (AOPs), especially the Fenton reaction, are highly effective due to their ability to generate powerful oxidizing species. However, the conventional homogeneous Fenton process has limitations, including the need for an acidic pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More and the generation of excess iron sludge. Heterogeneous Fenton systems offer a promising alternative by operating over broader pH ranges and allowing for catalyst recovery. This study leverages the unique properties of bacterial cellulose, an abundant and renewable material with high porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More and surface area, to create a novel catalytic support.

The researchers synthesized the BC-derived biochar by first purifying bacterial cellulose membranes and then modifying them with Fe2+/Fe3+ ions. This iron-impregnated material was subsequently calcined at 400∘C to produce the final catalytic biochar (KBPFC). The team evaluated the performance of three different treatment approaches: electrochemical degradation alone, a heterogeneous Fenton process alone, and a combined treatment integrating both methods. The results clearly demonstrated the superior efficiency of the combined treatment, highlighting its significant potential for practical applications.

A 23 factorial design was employed to assess the impact of key variables in the electrochemically assisted Fenton process: MB concentration, BC-derived biochar concentration, and reaction pH. Statistical analysis, yielding an R2 value of 0.989, revealed that only the dye concentration and biochar concentration had a statistically significant effect on the degradation efficiency. Importantly, the pH and interaction effects were found to be negligible, showcasing the versatility of the system across diverse media. For 10 ppm MB solutions, discoloration efficiencies reached nearly 80% within a maximum treatment time of 60 minutes, regardless of whether the pH was acidic or basic.

Further investigation into the total organic carbon (TOC) reduction confirmed the method’s efficiency in mineralizing the organic compound, not just decolorizing it. The TOC analysis showed a reduction of over 50% for both 10 ppm and 55 ppm MB solutions. This indicates a substantial breakdown of the dye into simpler, less harmful substances. A kinetic study further supported these findings, with the degradation process best fitting a first-order reaction model (R2=0.984), yielding a half-life of approximately 8.6 minutes for MB degradation.

The characterization of the biochar catalyst (KBPFC) provided insights into its enhanced properties. X-ray diffraction (XRD) patterns showed that after iron impregnation and calcination, the material exhibited the characteristic peaks of magnetite (Fe3​O4​) or maghemite (γ−Fe2​O3​), confirming the formation of crystalline iron oxide phases. Scanning electron microscopy (SEM) images revealed a uniform coating of inorganic particles on the bacterial cellulose surface, which persisted after thermal treatment, contributing to the final biochar formation. Nitrogen adsorption-desorption isotherms indicated that KBPFC possesses mesoporous characteristics, with a high surface area of 2.811 m2/g and a pore volume of 0.01820 cm3/g. These properties are highly advantageous for catalytic applications, as they promote better accessibility and dispersion of reactive sites.

Compared to previous studies on MB degradation, the proposed electrochemically assisted heterogeneous Fenton system with bacterial cellulose-derived biochar demonstrated competitive performance. It achieved high efficiencies (over 80% discoloration) and ranked among the fastest processes reported for MB degradation. The study concludes that this method is a promising and cost-effective alternative for treating MB dye and can be extended to the degradation of other organic compounds, offering a viable solution for industrial wastewater treatment.

Source: dos Santos, G. L., Barros, R. E. S., de Almeida, Y. A., Eguiluz, K. I. B., Salazar-Banda, G. R., & Gimenez, I. F. (2025). Bacterial Cellulose-Derived Biochar for Electrochemically Assisted Fenton Degradation of Methylene Blue. ACS Omega