Synthesis of a multicomponent cellulose-based absorbent for tetracycline removal from aquaculture water

Excessive use of tetracycline (TC) antibiotics in aquaculture, particularly in Vietnam, has contributed to environmental contamination and economic losses. To treat the problem, this study developed a novel cellulose-based multicomponent adsorbent material (PGC) synthesized from sodium carboxymethyl cellulose and investigated factors influencing its TC adsorption capacity. The synthesis process was optimized using parameters derived from response surface methodology. The surface and structural properties of PGC were characterized, and their TC adsorption efficiency of PGC was assessed using high-performance liquid chromatography‒mass spectroscopy (HPLC-MS). Elemental analysis of PGC identified four key mechanisms governing its endothermic TC adsorption mechanism: surface complexation, electrostatic interactions, hydrogen bonding, and CH–π interactions, with surface complexation between Ca ²⁺ and TCs being dominant. Batch adsorption experiments conducted to examine the factors influencing adsorption capacity revealed that PGC achieved up to 70% TC removal efficiency at an adsorbent dosage of 40 mg of the initial TC concentration of 60 mg L ^–1 , pH 6–7 reaching equilibrium in 12 h. Verification experiments under optimal conditions confirmed that the adsorption process followed second-order kinetics and the Langmuir adsorption isotherm model. These findings indicate that PGC demonstrates strong potential as an effective adsorbent for the removal of TC antibiotic residues, particularly oxytetracycline, chlortetracycline, TC, and doxycycline