Optimized copper-functionalized carbon from Lansium parasiticum trunk for chloramphenicol removal from aqueous solution

Abstract Chloramphenicol (Cp), a toxic antibiotic, poses significant risks to human health and aquatic ecosystems when released into the environment. This study investigates the removal of Cp from aqueous solution using copper-functionalized activated carbon derived from Lansium parasiticum trunk (Cu-MFCLT). The adsorbent was synthesized via microwave-assisted CO 2 activation followed by copper(II) nitrate, (Cu(NO 3 ) 2 ) surface modification. Optimal synthesis conditions were identified through response surface methodology (RSM), yielding a radiation power of 466.24 W, a duration of 13 min, and a metal loading rate (MLR) of 0.60 g/g. Under these conditions, the predicted Cp uptake capacity of 71.19 mg/g closely matched the experimental value of 73.66 mg/g, with an error of 3.35%. For Cu-MFCLT yield, the predicted and actual yield values were 52.75% and 51.11%, respectively (error of 3.21%). High R 2 values of 0.9441 and 0.9392 confirmed the reliability of the RSM models for Cp uptake and Cu-MFCLT yield, respectively. The optimized Cu-MFCLT showed a BET surface area (BET-SA) of 866.86 m 2 /g and a mesopore surface area (MESO-SA) of 627.17 m 2 /g. Adsorption equilibrium followed the Langmuir model, indicating monolayer coverage with a maximum adsorption capacity, Q m of 129.58 mg/g. Kinetic studies followed the pseudo-first-order (PFO) model, with k₁ values decreasing from 0.77 to 0.39 h −1 as Cp concentration increased from 10 to 100 mg/L. After five regeneration cycles, thermal microwave regeneration reduced Cp removal to 10.85% and Cu-MFCLT yield to 4.45%, whereas ethanol solvent regeneration maintained 65.82% Cp removal and 73.52% Cu-MFCLT yield, confirming ethanol as the superior regeneration method.