<p>The textile industry’s hazardous heavy metals and dyes are a significant environmental concern. This study presents an eco-friendly synthesis of silver nanoparticles (AgNPs) using <i>Zanthoxylum armatum</i> seed extract, providing a green and sustainable approach that eliminates the need for toxic precursors. The phytochemicals in the extract not only facilitate nanoparticle formation but also enhance catalytic efficiency for pollutants. The synthesised AgNPs exhibited remarkable performance in adsorbing and reducing heavy metals such as Cu (95.5%), Cd (98.4%), Cr (94.2%), Pb (92.3%), Ni (93.8%), Fe (90.23%), and Co (83.65%) within 10 minutes, outperforming ZnO, TiO₂, and biogenic nanoparticles in both efficiency and speed. This study is novel in its application of thermodynamic and kinetic models, offering a detailed evaluation of factors influencing the adsorption process. Key findings include the impact of nanoparticle size, temperature, contact time, adsorbent dosage, and pH on efficiency. Atomic absorption spectroscopy (AAS) confirmed high precision in the removal of metal ions. The AgNPs also demonstrated superior selectivity for hazardous ions like Cd^{2 +} and Fe^{3 +}, detected via colourimetric changes and UV- Vis spectroscopy. AgNPs show dual functionality of rapid detection of ions and high efficiency of removing them. The AgNPs maintained more than 80% of their adsorption efficiency even after eight regeneration cycles, with Ag⁺ leaching levels significantly below WHO limits, demonstrating their structural robustness and environmental safety. This study stands out for its thorough evaluation of recyclability and long-term stability. It also highlights ecotoxicological safety, as the phytochemical-capped nanoparticles show low environmental reactivity and controlled ion release, and it addresses important scalability issues by optimising extract yield and synthesis costs using locally available seed biomass. Furthermore, the AgNPs were validated in real textile effluent from Buddha Nullah (Ludhiana), showing up to 98% removal of heavy metals like Cd, Cu, and Ni under ambient sunlight. Statistical analysis using ANOVA confirmed the significance of differences in removal efficiency, particularly highlighting selective adsorption behaviour. By combining green synthesis with high efficiency, mechanistic clarity, safety, and scalability—an integrated advancement rarely addressed in prior nanoremediation studies—these findings collectively provide a revolutionary and economical solution for industrial wastewater remediation.</p>