CNT@NiFe₂O₄ nanocomposite for phenobarbital removal: adsorption study and characterization

The contamination of seas, rivers, lakes, and groundwater by industrial, hospital, and domestic effluents is a global health problem. Scientific approaches are needed to assess and mitigate the impacts of those pollutants, seeking more sustainable alternatives that meet established environmental standards. Among the various contaminants that are released into water sources, phenobarbital (PHEN), a long-acting barbiturate, applied as a hypnotic, sedative, and in the treatment of seizures is an aquatic pollutant, raises significant concerns for human health and the environment. Based on the high surface area of carbon nanotubes (CNTs) and the magnetic properties of nickel ferrite (NiFe₂O₄) nanoparticles, this work presents, for the first time, the application of CNT@NiFe₂O₄ on the adsorption of PHEN. The employing of CNT as a barbiturate adsorber was investigated, using NiFe₂O nanoparticles as a magnetic tool for recovering the nanocomposite from water. The PHEN adsorption study was performed in batch adsorption mode. Thermodynamic isotherms and kinect were performed using Langmuir, Freundlich, Sips, pseudo-first-order (PFO), pseudo-second-order (PSO), and Elovich diffusion models. CNT@NiFe2O4 showed an adsorption capacity of 76% for this drug, indicating it is a promising nanomaterial for removing PHEN from water.