In-Field ⁵⁷Fe Mössbauer study of maghemite nanoparticles functionalized multiwall carbon nanotubes and their ecotoxicological properties in young Daphnia magna

Multiwall carbon nanotubes functionalized with 13.8(6) nm maghemite nanoparticles (NPs) have been synthesized by a modified co-precipitation chemical route and characterized using N₂ physisorption and in-field ⁵⁷Fe Mössbauer studies. Textural and hyperfine magnetic properties indicated that this nanohybrid has a strong potential to be applied in magnetic remediation process due to their unique surface features. Moreover, acute toxicity evaluations were performed before in situ applications, where we implemented our nanohybrid in an effluent containing young Daphnia magna biomarker having a mortality percentage not higher than 15% for the selected concentrations. Despite of it, the reproduction rate was affected after two weeks of previous 72 h exposure, but without apparent morphological changes according to optical and scanning electron microscopy. These findings are of crucial interest for long term applications of concentrated NPs in polluted effluents.