Efficient ciprofloxacin removal from water using Zn-MOF and Date seeds-biochar composites: a comprehensive evaluation of greenness, sustainability, and environmental impact

Antibiotics, particularly ciprofloxacin (CIP), are emerging pollutants in ecosystems due to their widespread use, posing significant risks to human health and ecological balance. In this study, the adsorption potential of Date Seeds-Biochar (DS-Biochar) and a 10% Metal-Organic Framework (MOF) composite for CIP removal from wastewater was evaluated. The synthesised adsorbents were characterised using different tools. Batch adsorption experiments were optimised at pH 9, an adsorbent dose of 0.1 g/20 mL, CIP concentration of 50 mg/L, and a contact time of 120 minutes. The adsorption kinetics followed the pseudo-second-order model (R-2 = 0.998 for DS-Biochar, R-2 = 0.997 for the MOF composite), suggesting chemisorption as the rate-controlling mechanism. Equilibrium data fit the Sips isotherm for DS-Biochar (R-2 = 0.995) and Langmuir model for the MOF composite (R-2 = 0.996), with maximum adsorption capacities (qmax) reaching 218 mg/g for DS-Biochar and 300 mg/g for the MOF composite. Thermodynamic studies revealed that the adsorption process is spontaneous, endothermic (Delta H > 0), and entropy-driven (Delta S > 0), though less favourable at higher temperatures. Both materials demonstrated excellent reusability, maintaining high removal efficiencies over four regeneration cycles. Cytotoxicity assays indicated superior biocompatibility. Antimicrobial evaluations highlighted the enhanced activity of Zn-MOF-based materials.