Microwave‐Assisted Sodium Carbonate Activation of Fennel and Caraway Seeds for Sustainable Dye Removal from Water Systems

This study investigates the production of carbon adsorbents from agricultural precursors (caraway and fennel seeds) using microwave-assisted activation with sodium carbonate, aiming to develop cost-effective materials for wastewater treatment. The prepared carbons exhibited specific surface areas of 25-26 m² g^-1 and predominantly acidic surface functional groups. Their adsorption performance is evaluated for the removal of methyl red (MR) and methylene blue (MB), with maximum adsorption capacities of 32-39 mg g^-1 for MR and 68-91 mg g^-1 for MB. Adsorption follows pseudo-second-order kinetics, while thermodynamic analysis confirms that the process is spontaneous and endothermic. Compared with conventional activation methods, the proposed microwave-assisted route reduces processing time and energy demand. These results demonstrate that microwave-assisted sodium carbonate activation of agricultural residues is a promising strategy for producing sustainable sorbents applicable to organic dye removal in real wastewater systems.