Effective Methylene Dye Removal from Contaminated Water using Zinc Oxide Nanoparticles Fabricated from the Green Synthesis of Laurus nobilis Leaf

Methylene blue (MB), a prevalent pollutant in textile industry wastewater, poses significant environmental and health risks due to its toxicity, mutagenicity, and persistence. Effective remediation strategies are essential for mitigating its impact. This study presents a novel approach using Zinc Oxide (ZnO) nanoparticles synthesized via a green synthesis method employing Laurus nobilis leaf extract. This environmentally friendly method avoids harmful chemicals and enhances the safety of nanoparticle disposal. The ZnO nanoparticles, characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR), were monodispersed with an average size of 68.5 nm and showed excellent morphological properties. The nanoparticles achieved a maximum dye removal efficiency of 99% under optimal conditions of pH 3 and a contact time of 150 minutes. The maximum adsorption capacity of the ZnO nanoparticles for MB was 33.75 mg/g. The adsorption kinetics and isotherms were effectively described by the pseudo-second-order kinetic model and both the Freundlich and Langmuir adsorption models, with the Langmuir model indicating a monolayer adsorption capacity of 30.98 mg/g. The correlation coefficients (R2) for the Langmuir and Freundlich models were 0.9421 and 0.9463, respectively, demonstrating the robustness of these models in describing the adsorption behaviour. This study not only underscores the potential of green synthesized ZnO as an effective adsorbent for dye remediation but also contributes significantly to sustainable practices in environmental management.

Doga Kavaz