In Situ and after Synthesis of Magnetic Nanoarchitectures Grown onto Zeolite Type 5A/CTAB Frameworks and Their Ecotoxicological Properties

Controlled-size maghemite (γ-Fe₂O₃) nanoparticles (NPs) were functionalized with zeolite 5A and cetyltrimethylammonium bromide (CTAB) by the co-precipitation method. The in situ and after NPs synthesis procedures were used to obtain five different nanomaterials that were broadly characterized by various physicochemical methods to ensure magnetic remediation properties. γ-Fe₂O₃ NPs with sizes ranging from 4.5 to 12 nm were obtained for bare NPs and also dispersed in matrices of zeolites and CTAB. Acute toxicity tests were systematically performed in the freshwater biomarker microcrustacean Daphnia magna to figure out the impact of these nanohybrids in living beings that are part of real effluents. The lethal concentrations were found to range from 103.2 mg L⁻¹for bare γ-Fe₂O₃ NPs to 0.5 mg L^-1 for the series of nanohybrids studied here. Morphological analysis of living beings showed some significant changes in their vital structures (heart and eye) and some malformations in some part of their eyes. This study has provided novel information on the magnetic properties of bare and functionalized iron oxide based NPs and, more relevant, their interactions and impacts on the cladoceran D. magna under controlled conditions that could be expanded to real environments after industrial water treatment.