Publication: Synthesis of microwave-assisted sago bark based activated carbon for antibiotics removal: batch, optimization and regeneration studies.
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Date
2025-12
Authors
Baharom, Siti Zawiyah
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Abstract
The existing of amoxicillin (AMOX) and chloramphenicol (CAP) in aquatic environments have detrimental effects on the aquatic ecosystem. This study focused on developing sago bark-based activated carbon (SBAC) by using a combination of KOH and CO₂ activation, along with microwave irradiation for the removal of AMOX and CAP from aqueous solutions. According to response surface methodology (RSM), the optimum preparation conditions for SBAC were 596 watts for radiation power, 10.70 minutes for radiation time, and an impregnation ratio (IR) of 1.70 g/g. These conditions were predicted to achieve AMOX and CAP removal capacities of 80.50 mg/g and 74.81 mg/g, respectively, with an SBAC yield of 27.90%. Characterization of optimized SBAC showed a BET surface area of 1023.58 m²/g, a mesoporous surface area of 755.63 m²/g, and an average pore diameter of 2.87 nm. The adsorption capacity of AMOX and CAP by SBAC increased with higher initial concentrations and longer contact times. Isotherm studies demonstrated that both AMOX-SBAC and CAP SBAC systems conformed to the Freundlich model, with maximum adsorption capacity, Qm of 110.52 mg/g for AMOX and 131.83 mg/g for CAP. Kinetic studies revealed that both systems followed the pseudo-first-order (PFO) model, with film diffusion identified as the rate-limiting step based on Boyd plot analysis. Thermodynamic analysis indicated that the adsorption processes were exothermic, spontaneous, and governed by physisorption. The adsorption of antibiotics onto SBAC was facilitated by hydrogen bonding, dipole-dipole interactions, and π-π interactions. SBAC maintained effective performance for up to three regeneration cycles, with AMOX and CAP removal exceeding 50%.