Efficient removal of methylene blue using Azolla/biochar composite: adsorption behavior and post-use valorization for...

The use of green and sustainable chemistry offers an efficient approach for synthesized innovative materials to address wastewater treatment challenges with declined energy consumption. This study addressed the significant global issues of water pollution from industrialization and population growth by designing cost effective, high-capacity materials utilizing for the removal of Methylene blue dye (MB). A novel bio-composite material (AZ/BC) was synthesized by amalgamating Azolla pinnata extract and biochar by ultrasonication technique. The resultant biomaterials were evaluated using techniques such as XRD, FTIR, and SEM to examine its surface appearance and crystalline structure. Batch adsorption experiments were conducted determine optimal conditions for MB removal, while Monte Carlo simulations were validated the molecules interaction between MB and the AZ/BC surface. The synthesized AZ/BC biomaterial exhibited a successful structural transition to uniformly stacked layers with high porosity, attaining a maximum methylene blue removal effectiveness of 96.21% within 120 min. Adsorption kinetics followed a pseudo-second-order model, and the Langmuir isothermal best described the monolayer adsorption process. Additionally, the used adsorbent was effectively repurposed as an efficient electrocatalyst for methanol oxidation in fuel cells, demonstrating excellent stability and highlighting a sustainable approach for energy production from wastewater treatment material.