We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Macroscopic and microscopic investigation of adsorption mechanisms of phenanthrene and its derivatives on polyacrylonitrile microplastics
Summary
This study investigated how polyacrylonitrile (PAN) microplastics adsorb phenanthrene and four of its chemical derivatives from water, finding that the type of functional group on the pollutant strongly controls how much and how fast it sticks to the plastic. Substituted forms with nitro or chlorine groups adsorbed more strongly than plain phenanthrene. This matters because microplastics can act as carriers of toxic organic pollutants in the environment, and understanding which pollutants bind most readily helps predict contamination risks in aquatic ecosystems.
To investigate the adsorption behavior and molecular mechanisms of polyacrylonitrile (PAN) microplastics (MPs) toward phenanthrene (PHE) and its four derivatives: PHE-CH, PHE-CHO, PHECl, and PHE-NO, the adsorption kinetics, isotherms, and interaction mechanisms of the above five target pollutants were systematically studied and compared by macroscopic adsorption experiments combined with microscopic spectral technology. The results showed that the adsorption capacity of PAN for the target pollutants follows the order: PHE-NO > PHE-Cl > PHE-CH > PHE-CHO > PHE, and the adsorption process reached equilibrium within 8 h. Kinetic and isotherm models further revealed that the type of derivatives had a significant impact on the adsorption behavior: PHE, PHE-CHO, PHECl, and PHE-NO were mainly adsorbed through chemical adsorption, while the adsorption of PHE-CH was dominated primarily by physical diffusion. Fourier transform infrared spectroscopy and two-dimensional correlation spectroscopic analyses revealed that different derivatives regulated intermolecular forces such as hydrophobic interactions, hydrogen bonding, halogen bonding, and π-π stacking, thereby governing the adsorption pathways and efficiency. This study provides theoretical insights at the mechanistic level for understanding the combined pollution behavior of MPs and PHE and its derivatives, offering important reference value for ecological risk assessment.