Activated carbon derived from almond tree dry leaves waste for enhanced multi dye removal from aqueous solutions

[Display omitted] •Activated carbon is successfully derived from almond dry leaves waste.•Near-complete (>95%) removal of dyes attained at fixed-bed column method.•Regeneration studies proved that adsorbent is efficient after 5 recycles.•The process is aligned with the conversion of natural waste to value-added material. In this research, the activated carbon (AC) was synthesized from the natural waste of almond dry leaves (ADL) using ZnCl2 (1:1 ratio) activation combined with carbonization (450 °C/2h). The resultant almond dry leaves activated carbon (ADLAC) Surface area (681 m2 g−1), total pore volume (0.63 cm3 g−1) was analyzed by Branueur-Emmett-Teller (BET) analysis. The further instrumental analyses revealed the surface texture with pore distribution, rich carbon content (78.18 wt%), and functional groups associated with the surface of ADLAC. The near-complete (>96%) dye removal efficiency of ADLAC has been recorded on the multi-dye solutions in the fixed bed column (FBC) experiment. The regeneration studies exhibited only 4–5% loss in the actual behavior of ADLAC on the fifth recycle. It is observed that the implemented condition of ZnCl2 activation and carbonization can be an effective method to convert ADL waste as a usable adsorbent for dye removal.