Removal of Dyes from Wastewater by Adsorption on Abies Pindrow Cone

Dyes are widely used across industries such as textiles, cosmetics, and pigments, with global annual production exceeding 7 × 105 tons. Dye pollution from industrial wastewater poses significant environmental challenges, necessitating the development of efficient and sustainable adsorbents. Silver nanoparticles (AgNPs) synthesized from Abies pindrow cone extract (APC-Ag-NPs) via an environmentally friendly green reduction method were investigated for their efficacy in removing methylene blue (MB) dye from aqueous solutions. The prepared APC-Ag-NPs were comprehensively characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS), and zeta potential analysis to elucidate their structural, morphological, and colloidal properties. Adsorption experiments systematically examined the effects of adsorbent dosage, particle size, initial dye concentration, and temperature on MB removal efficiency. The results demonstrated that smaller particle sizes (40–60 nm) achieved a superior dye removal efficiency of up to 95%, attributable to their increased surface area. Additionally, higher initial dye concentrations enhanced adsorption due to greater concentration gradients. The optimal removal efficiency (92%) was observed at an adsorbent dosage of 0.5 g/L, while higher dosages resulted in reduced performance, likely due to underutilization of active sites. Increasing the temperature led to a decrease in adsorption capacity, indicating that the process is exothermic. Kinetic studies revealed that the adsorption suggesting multilayer adsorption on heterogeneous surfaces. This study underscores the potential of APC-Ag-NPs as a cost-effective and environmentally sustainable adsorbent for dye removal in wastewater treatment, offering a promising and scalable solution for environmental remediation. © 2025 Elsevier B.V., All rights reserved.