In this study, nanographite was employed as a sustainable and efficient adsorbent for the removal of toxic nickel(II) ions from real industrial electroplating wastewater, characterized by a high initial concentration of 783 mg L⁻¹. The nanographite (99.9% purity; flake thickness 5–20 nm; specific surface area 18–24 m²/g) was systematically characterized via FE-SEM analysis to elucidate its morphological features. Batch adsorption experiments were conducted using a one-factor-at-a-time (OFAT) approach to evaluate the influences of key operational parameters, including solution pH, contact time, and adsorbent dosage.

The results demonstrated that solution pH was the critical governing factor; nickel removal efficiency increased significantly from negligible levels under strong acidic conditions to 94.51% at an optimum pH of 7.0. Kinetic and equilibrium studies revealed that the adsorption process attained 95.42% removal efficiency within 80 min using 1.0 g of adsorbent, achieving an overall maximum removal of 97.52%. Adsorption isotherm data exhibited the best fit to the Freundlich model, implying a multi-layer adsorption mechanism on a heterogeneous surface. Furthermore, the adsorption kinetics were effectively described by the pseudo-second-order model, suggesting that the process is chemisorption-controlled. These findings highlight the potential of nanographite as a high-performance, low-cost material for the advanced treatment of nickel-bearing industrial effluents, providing a scalable solution for heavy metal remediation in environmental engineering.