We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Unveiling the Modulatory Role of Microplastics in the Release of Chlorinated Organophosphorus Flame Retardants from Landfill Soils
Summary
Microplastics and toxic flame retardants (Cl-OPFRs) often co-exist in landfill soils, and this study reveals that the plastics actually slow down how quickly the chemicals are released into the surrounding environment. The type of plastic matters: polar plastics like PVC and nylon hold onto flame retardants through electrostatic attraction, while non-polar plastics like polyethylene and polypropylene rely on hydrophobic interactions. This finding is important for understanding whether microplastics in landfills are reducing or delaying chemical risks — and whether they might eventually release concentrated bursts of toxic compounds.
Landfills are significant reservoirs of chlorinated organophosphorus flame retardants (Cl-OPFRs) and microplastics (MPs), yet their interactions remain unclear. This study systematically revealed that MPs in landfill soils significantly inhibited the release of Cl-OPFRs, with a dose-dependent effect (up to 27.69% reduction). Release kinetics followed the pseudo-second-order kinetics (R = 0.747-0.986), indicating chemically controlled processes. Molecular modeling confirmed that polar interactions governed the adsorption of Cl-OPFRs onto polar MPs (PA, PVC), while hydrophobic interactions prevailed for non-polar MPs (PE, PP). Ionic strength showed a non-monotonic effect, with low levels (0.01-0.1 M NaCl) enhancing the release process through competitive adsorption, whereas a high levels suppressed it via salting-out and double-layer compression. Both acidic and alkaline conditions promoted the release of Cl-OPFRs, likely resulting from changes surface charges and competitive ion effects. Fulvic acid showed a concentration-dependent dual effect. Critically, structural equation modeling identified ionic strength and soil organic matter as the primary factor governing the release of hydrophilic and hydrophobic Cl-OPFRs, respectively. These findings provide mechanistic insights essential for assessing the mobility and risks of Cl-OPFRs in MPs-contaminated landfills.