<p>In the present study, highly porous activated carbon (AC) was synthesised from <i>Prosopis juliflora</i> pods with a utilisation of NaOH-assisted chemical activation to investigate its adsorption efficiency, adsorption mechanism as well as reusability performance to remove Malachite Green (MG) dye from an aqueous solution. SEM and BET analyses confirmed high surface area of 1710.2&#xa0;m² g⁻¹ with a porous and heterogeneous surface morphology. Batch experiments were performed by varying operational parameters to evaluate an adsorption performance. There are several studies on biomass-derived adsorbents where as utilisation of <i>Prosopis juliflora</i> pod-derived AC (PJAC) for MG removal is limitedly explored. The adsorption equilibrium was reached approximately at 210&#xa0;min, with maximum MG removal efficiency of 136.43 mg g⁻¹. The adsorption remained highly effective across a wide concentration range (50–300 ppm). Adsorption was strongly pH-dependent, at pH 3 the performance was very poor but consistently high removal within wide range of pH 4–10. Equilibrium data were best fitted for Langmuir isotherm, indicating monolayer adsorption with a maximum capacity of 136.43&#xa0;mg g⁻¹. Kinetic analysis revealed that the process follows a pseudo-second-order model. Mechanistic insights from FT-IR confirmed the involvement of electrostatic attraction, hydrogen bonding, and π–π interactions. This activated carbon can be reused up to four cycles. The findings highlight the potential of PJAC as an efficient, low-cost, and environmentally sustainable material for dye-contaminated wastewater treatment.</p> Graphical abstract <p></p>