The pervasive co-existence of microplastics with other pollutants complicates the efficacy of adsorbents in water remediation. This study, therefore, investigates the under-explored impact of polypropylene (PP) and polystyrene (PS) microplastics on the adsorption of Cu2+ by a novel β-cyclodextrin modified biochar (β-BC). Results revealed a significant inhibition of Cu2+ removal in the presence of both microplastics, with the Langmuir maximum adsorption capacity decreasing from 38.12 mg/g for β-BC alone to 33.03 mg/g with PP and 29.07 mg/g with PS. The stronger inhibition by PS is attributed to surface site coverage via π-π stacking interactions, whereas PP’s interference stems primarily from physical pore blockage. Furthermore, the inhibitory effect was pH-dependent, while high salinity or humic acid concentrations unexpectedly promoted the overall Cu2+ uptake, highlighting the complex role of environmental factors. This work underscores the critical need to consider microplastic interference when evaluating adsorbents for real-world environmental applications.
Tong, H., Gong, X., Wu, F. et al. Effect of Microplastics on Cu2+ Adsorption by β-cyclodextrin Modified Biochar. Water Air Soil Pollut 237, 118 (2026). https://doi.org/10.1007/s11270-025-08688-3