Self-sustained carbonization and high-temperature activation of bamboo (Dendrocalamus asper (Schult. & Schult.f.) Backer and Bambusa vulgaris Schrad. ex J.C.Wendl.) for high ammoniacal nitrogen removal

Ammoniacal nitrogen (NH 3 N) is a critical water pollutant that requires efficient and sustainable removal strategies. This study reports the synthesis of high-performance activated carbon from Dendrocalamus asper and Bambusa vulgaris via an integrated self-sustained carbonization and H₃PO₄ activation approach. The physicochemical properties of the adsorbents were systematically characterized using BET, FESEM-EDX and FTIR analyses. The prepared activated carbons exhibited highly developed micro–mesoporous structures, with B. vulgaris demonstrating a superior surface area (1712.58 m²/g) compared to D. asper (1561.55 m²/g). Process optimization using a Box–Behnken design revealed that adsorbent dosage, agitation rate and contact time significantly influenced NH 3 N removal, achieving maximum efficiencies of 75.58% for D. asper and 77.68% for B. vulgaris . The adsorption equilibrium was most accurately represented by the Freundlich isotherm, suggesting a heterogeneous surface with multilayer adsorption. The kinetic data were best fitted by a pseudo-second-order model, indicating that chemisorption is the dominant mechanism controlling the adsorption process. Notably, B. vulgaris exhibited a markedly higher adsorption capacity (235.41 mg/g) than D. asper (114.12 mg/g), outperforming many reported bio-based adsorbents. These findings demonstrate that bamboo-derived activated carbon, particularly from B. vulgaris , offers a scalable, low-cost and sustainable solution for effective ammoniacal nitrogen removal in wastewater treatment applications.