The capture of 1-chloronaphthalene by poly (butyleneadipate-co-terephthalate) and polylactic acid in seawater

Biodegradable plastics, widely recognized as promising substitutes for conventional plastics, still face the challenge of microplastic contamination to require in-depth assessments of combined pollution scenarios. This study explored the adsorption of 1-chloronaphthalene (PCN-1) by biodegradable plastics including poly(butylene adipate-co-terephthalate) (PBAT) and polylactic acid (PLA) with polyethylene (PE) as a conventional plastic control in seawater. The maximum adsorption capacity of PCN-1 on PLA/PBAT/PE in seawater reached 131.22/323.59/301.80 μg g −1 . The desorption efficiency of PCN-1 from PLA and PBAT was substantially lower than that from PE, suggesting that biodegradable plastics might pose reduced environmental risks due to low pollutant release. Interaction between PCN-1 and biodegradable plastics could be regulated by pH, which was attributed to the modulation of π-π stacking interactions. Salinity exerted a positive effect on the adsorption capacity of PCN-1 by PLA, PBAT, and PE; the maximum capacities (131.22/323.59/301.80 μg g −1 , respectively) were achieved at a salinity of 30‰. Pseudo-second-order model obtained good fitting on adsorption kinetics of PCN-1 on PLA while PBAT and PE exhibited higher consistency with the pseudo-first-order model. Thermodynamic analysis based on enthalpy (ΔH) and Gibbs free energy (ΔG) changes revealed that PCN-1 adsorption on PLA was an endothermic process, while the adsorption on PBAT and PE was exothermic. Collectively, the capture of PCN-1 by biodegradable plastics is predominantly governed by three key factors: crystallinity of the plastic matrix, π-π interaction between the plastic and PCN-1, and hydrophobic interaction.