<p>This study introduces a novel and sustainable method for the removal of the heavy metals nickel and chromium from aqueous solutions using modified microcellulose. The modification process utilizes green tea extract and iron sulfate to enhance the surface and structural properties of microcellulose, significantly improving its adsorption performance. X-ray diffraction (XRD) analysis revealed an increase in the crystallinity index from 93 to 98% following modification. Scanning electron microscopy (SEM) showed that the diameter of the modified cellulose fibers reached approximately 6.75&#xa0;µm. The Brunauer–Emmett–Teller (BET) surface area increased from 1.7 to 2.98 m²/g, while the pore volume nearly doubled compared to unmodified cellulose, indicating enhanced surface characteristics. Particle size distribution analysis showed a reduction in particle size, with a range of 1 to 500&#xa0;µm. The maximum adsorption capacities were calculated as 8.702&#xa0;mg/g for chromium and 3.949&#xa0;mg/g for nickel. The removal efficiencies reached 81% for chromium and 16% for nickel. These results demonstrate the promising potential of green-modified microcellulose as an effective, eco-friendly adsorbent for water treatment applications.</p> Graphical Abstract <p></p>