High performance adsorptive removal of emerging contaminant paracetamol using a sustainable biobased mesoporous activated carbon prepared from palm leaves waste

In this work, a novel bio-based carbon material was prepared via a facile pyrolysis method using chemically activated dead palm leaves as a sustainable and efficient carbon precursor. The as-prepared activated carbon with KOH activation (AC-KOH) was characterized by XRD, FTIR, SEM, EDS, and BET analysis. The AC-KOH was used for the adsorption of paracetamol (PCT) from aqueous solutions and the effect of experimental conditions such as contact time (0.08–30 hours), pH (2.96–12.1), initial drug concentration (1–50 mg L⁻¹), adsorbent dosage (0.12–1.2 g L⁻¹), and temperature (25–45 °C) was investigated. The system achieved equilibrium in 4 hours and PCT uptake was highly dependent on solution pH. A maximum removal efficiency was achieved at a pH of around 5.86. Kinetic model analysis indicated that the uptake follows the pseudo-second-order model (R² = 0.989). The maximum monolayer capacity of the developed AC for PCT was found to be 87.87 mg g⁻¹ at time of equilibrium (4 hours), solution pH of 5.86, adsorbent dose of 0.2 g L⁻¹, concentration of 1–50 mg L⁻¹ and temperature of 25 °C. The PCT uptake process was feasible, spontaneous (ΔG⁰ < 0), and endothermic (ΔH⁰ > 0) according to the thermodynamics evaluation. The mechanism of PCT adsorption primarily involved pore-filling, π-π interaction, and H-bonding. The adsorbent exhibited reasonable reusability towards PCT adsorption up to two regeneration cycles. The results of this work support that the dead palm leaves are efficient, cheap, and sustainable feedstock for producing activated carbon adsorbent to be used for an efficient removal of PCT from real wastewater samples.