In-situ and Ex-situ synthesized activated carbons derived from Raphia hookeri Kernels for ibuprofen adsorption in wastewater

Abstract

This study introduces an innovative approach to synthesizing activated carbon (AC) from Raphia hookeri kernels, optimizing its application for efficient ibuprofen removal from wastewater. By exploring two distinct activation pathways—in-situ and ex-situ—the research underscores the tailored performance of the resulting ACs. Comprehensive characterization included point-of-zero charge (pHpzc), Brunauer-Emmett-Teller (BET) analysis, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). BET analysis revealed surface areas of 260.932 and 273.863 m²g⁻¹ for in-situ and ex-situ ACs, respectively, emphasizing their high porosity. The adsorption efficiency was evaluated under various conditions: pH (2−10), adsorbent doses (0.05–0.15 g), contact times (20–200 min), and ibuprofen concentrations (2–10 mgL⁻¹). The ACs demonstrated robust performance in ibuprofen removal, with kinetic data aligning with the pseudo-second-order model. Notably, the in-situ AC exhibited heterogeneous surface and multilayer adsorption characteristics (KF = 13.94 mgg⁻¹), while the ex-situ AC showed monolayer adsorption behavior (qm = 23.14 mgg⁻¹). Both ACs maintained high capacities over multiple cycles, indicating effective regeneration and reuse, making them cost-efficient and sustainable for wastewater treatment. This study's innovation lies in systematically comparing activation pathways, offering a framework for customizing biomass precursors to enhance adsorption in wastewater management.