Valorizing Xanthoceras Sorbifolia Bunge seed coats: A novel lignin-based activated carbon for effective malachite green adsorption and wastewater treatment

In order to increase the added value of Xanthoceras Sorbifolia Bunge (XSB) and to obtain green biomass activated carbon with abundant pores for efficient MG removal, this study was the first to prepare XSB-based high-performance activated carbon using KOH activation. Activated at temperatures between 600 and 800 °C, XSBAC-800 exhibited the highest specific surface area (1580 m²/g) and pore volume (0.732 cm³/g), leading to superior MG adsorption. The maximum adsorption capacity (Q_m) of XSBAC-800 for MG was 1241.25 mg/g at 313 K, pH=7, and 0.2 g/L concentration. The adsorption process was spontaneous, endothermic, and driven by physical mechanisms such as pore filling and electrostatic interactions. XSBAC-800 also demonstrated excellent reusability, maintaining a removal percentage above 89 % after five regeneration cycles. These findings highlight the effectiveness of XSB-based activated carbon as a sustainable adsorbent for the removal of MG dyes, providing a promising solution for water pollution control.