Management of a ciprofloxacin as a contaminant of emerging concern in water using microalgaebioremediation: mechanism, modeling, and kinetic studies.

Pharmaceutical residues, now recognized as a new category of environmental pollutants, have potentially risks to both ecosystems and human health effects. Recently, biosorption has emerged as one of the most promising strategies for managing these pharmaceutical wastes in water. Nevertheless, the environmental impact of the adsorbents presents a challenge to the advancement of this process. Therefore, the present study proposed two biosorbent: Chlorella vulgaris and Synechocystis sp. microalgae to manage Ciprofloxacin (CIP) in water. The experimental findings revealed that the optimal conditions for adsorption conditions are CIP initial concentration 4.0 mg/L and pH 5 and 3 for Synechocystissp. and C. vulgaris, respectively. The adsorption process followed the Pseudo-second-order kinetic model. The main mechanism of biosorption is the complexation of CIP with carboxyl, hydroxyl, carbonyl, and amido groups which was confirmed by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDX) analyses. These analyses confirmed the presence of CIP on the surface of tested microalgal cells. These results indicated that the adsorption mechanism of CIP by Synechocystis sp. PCC6803 and C. vulgaris offers theoretical insights into the biosorption mechanisms of pharmaceutical residues.