Magnetic nanocellulose for losartan removal: Adsorption and ecotoxicity assessment.

Pharmaceutical contaminants in aquatic environments, such as the antihypertensive drug losartan, pose significant environmental and public health risks due to their persistence and ecotoxicity. Conventional wastewater treatment processes often fail to remove such micropollutants effectively, underscoring the need for innovative, sustainable remediation approaches. This study investigates magnetic nanocrystalline cellulose (NC·Fe₃O₄), a biodegradable, renewable, and magnetically recoverable material, as an efficient adsorbent for losartan removal from aqueous solutions. The nanocomposite was synthesized via co-precipitation and characterized using FTIR, XRD, SEM, EDS, Raman spectroscopy, and vibrating sample magnetometry (VSM). Batch adsorption experiments assessed parameters including pH, initial LOS concentration, adsorbent dosage, and ionic strength. Kinetics and equilibrium data were modeled using Elovich and Liu equations, while thermodynamics were analyzed via the Van't Hoff approach. Ecotoxicological assessments employed MTT assays on L929 fibroblasts and germination tests on Lactuca sativa seeds. The nanocomposite achieved 96.36 % removal efficiency at pH 4.0, exhibiting spontaneous/exothermic chemisorption. Its magnetic properties enabled straightforward recovery and reuse over six cycles with sustained performance. Toxicity evaluations revealed minimal cytotoxicity and enhanced seedling growth at certain concentrations. Overall, NC·Fe₃O₄ presents as a promising, eco-friendly, and reusable material for mitigating pharmaceutical pollutants, with potential applications in advanced wastewater treatment and pharmaceutical repositioning.