Synthesis and Characterization of Magnetic Chitosan/Biochar Microcomposite from Lamtoro Pod Husk (Leucaena leucocephala) as a Potential Adsorbent for Amoxicillin Remediation in Aquatic Systems Budi Hastuti & Najwa Rahma
Department of Chemistry Education, Faculty of Teacher Training and Education, Universitas Sebelas Maret (UNS)
Jalan Ir. Sutami No. 36A, Kentingan, Jebres, Surakarta 57126, Central Java, Indonesia
Email: najwarahma02[at]student.uns.ac.id
Abstract
This study aimed to synthesize and characterize a magnetic chitosan biochar microcomposite derived from lamtoro (Leucaena leucocephala) peel and to evaluate its adsorption performance toward amoxicillin. Biochar was activated with KOH at 700 C, Fe3O4 nanoparticles were synthesized via coprecipitation, and the Chi BLP Fe3O4 microcomposite was prepared using the ionic gelation method. FTIR characterization confirmed intercomponent interactions through hydrogen bonding, indicated by the shift of the OH band from 3430.55 cm-1 (chitosan) to 3406 cm-1 in the microcomposite, while the Fe O band at 443 cm-1 was retained. TGA DSC analysis showed that the thermal stability of the microcomposite (residue 15.16 percent) was intermediate between chitosan (25.75 percent) and BLP (76.52 percent), accompanied by the appearance of a new exothermic peak at approximately 440 C. PSA results revealed an increase in Z average from 201.1 nm (chitosan) to 761.7 nm (microcomposite). SEM analysis demonstrated a morphological transformation from a smooth surface to a rough and heterogeneous structure, with particle diameter following the order: Fe3O4 (34.92 nm) less than chitosan (50.67 nm) less than BLP (129.43 nm) less than composite (793.51 nm). Adsorption studies indicated an equilibrium time of 30 minutes, with an adsorption capacity (qe) of 0.804 mg g-1 and adsorption efficiency (EA) of 4.741 percent at pH 6.0. All characterization results confirmed the successful synthesis of the magnetic Chi BLP Fe3O4 microcomposite, demonstrating its potential application as an adsorbent for amoxicillin remediation in aquatic systems.
