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The rise in cyanobacterial blooms due to eutrophication and climate change has increased cyanotoxin presence in water. Most current water treatment plants do not effectively remove these toxins, posing a potential risk to public health. This study introduces a water treatment approach using nanostructured beads containing magnetic nanoparticles (MNPs) for easy removal from liquid suspension, coated with different adsorbent materials to eliminate cyanotoxins. Thirteen particle types were produced using activated carbon, CMK-3 mesoporous carbon, graphene, chitosan, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidised cellulose nanofibers (TOCNF), esterified pectin, and calcined lignin as an adsorbent component. The particles' effectiveness for detoxification of microcystin-LR (MC-LR), cylindrospermopsin (CYN), and anatoxin-A (ATX-A) was assessed in an aqueous solution. Two particle compositions presented the best adsorption characteristics for the most common cyanotoxins. In the conditions tested, mesoporous carbon nanostructured particles, P1-CMK3, provide good removal of MC-LR and Merck-activated carbon nanostructured particles, P9-MAC, can remove ATX-A and CYN with high and fair efficacy, respectively. Additionally, in vitro toxicity of water treated with each particle type was evaluated in cultured cell lines, revealing no alteration of viability in human renal, neuronal, hepatic, and intestinal cells. Although further research is needed to fully characterise this new water treatment approach, it appears to be a safe, practical, and effective method for eliminating cyanotoxins from water. [ABSTRACT FROM AUTHOR]

Challenging magnetic hyperthermia (MH) applications of immobilized magnetic nanoparticles require detailed knowledge of the effective anisotropy constant (Keff) to maximize heat release. Designing optimal MH experiments entails the precise determination of magnetic properties, which are, however, affected by the unavoidable concurrence of magnetic interactions in common experimental conditions. In this work, a mean‐field energy barrier model (ΔE), accounting for anisotropy (EA) and magnetic dipolar (ED) energy, is proposed and used in combination with AC measurements to a specifically developed model system of spherical magnetic nanoparticles with well‐controlled silica shells, acting as a spacer between the magnetic cores. This approach makes it possible to experimentally demonstrate the mean field dipolar interaction energy prediction with the interparticle distance, dij, ED≈ 1/dij3 and obtain the EA as the asymptotic limit for very large dij. In doing so, Keff uncoupled from interaction contributions is obtained for the model system (iron oxide cores with average sizes of 8.1, 10.2, and 15.3 nm) revealing to be 48, 23, and 11 kJ m−3, respectively, close to bulk magnetite/maghemite values and independent from the specific spacing shell thicknesses selected for the study. [ABSTRACT FROM AUTHOR]