Optimization and kinetic modeling of ciprofloxacin adsorption and photocatalytic degradation in water

The persistent presence of pharmaceutical residues in aquatic environments presents a significant ecological and public health challenge, necessitating innovative and sustainable remediation strategies. This study investigates the dual functionality of a synthesized nickel-aluminum layered double hydroxide (Ni-Al LDH) composite for the efficient removal of ciprofloxacin (CIP), a widely used antibiotic, from wastewater through both adsorption and photocatalytic degradation processes. The Ni-Al LDH was synthesized via co-precipitation and characterized using FE-SEM, EDX, XRD, FTIR, XPS, TGA, and BET techniques. Adsorption experiments demonstrated a maximum adsorption capacity of 14.03 mg g^{- 1} under optimized conditions, including an initial CIP concentration of 20 mg L^{- 1}, a contact time of 5 min, an adsorbent dosage of 0.125 g L^{- 1}, and a pH of 11. The photocatalytic degradation under solar irradiation achieved a removal efficiency of 78.7% at 60 min using 0.02 g of catalyst and an initial CIP concentration of 15 mg L^{- 1}. The kinetics and adsorption isotherm modeling confirmed the material's high reactivity and affinity toward CIP. The novelty of this work lies in the application of dual-function Ni-Al LDH for the removal of a pharmaceutical pollutant, demonstrating rapid adsorption kinetics and an enhanced photocatalytic activity, a solar-driven, and a green approach involving ethanol and plant-based reagents for material regeneration, aligning with the sustainable water treatment goals. These findings highlight the material's promise as an eco-friendly and efficient candidate for practical wastewater treatment applications.