Biological effects of four iron-containing nanoremediation materials on the green alga Chlamydomonas sp

• Published in: Ecotoxicology and environmental safety Vol. 154; pp. 36 - 44
• Main Authors: Nguyen, Nhung H.A., Von Moos, Nadia R., Slaveykova, Vera I., Mackenzie, Katrin, Meckenstock, Rainer U., Thűmmler, Silke, Bosch, Julian, Ševců, Alena
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 15.06.2018
• Subjects: adsorption; algae; aquatic environment; Biological effect; carbon; Carbo‐Iron; Chlamydomonas; Chlamydomonas sp; chlorophyll; color; ecotoxicology; FerMEG12; groundwater; iron; iron oxyhydroxides; nanoparticles; Nano‐Goethite; oxidation; photosystem II; reactive oxygen species; toxicity; Trap-Ox Fe-zeolite; zeolites; zeta potential; AC; Trap-Ox Fe-zeolite; Chlamydomonas sp; PSII; QY; DLS; nZVI; ORP; ZVI; FU; FerMEG12; FCM; FE SEM; Nano‐Goethite; ROS; PI; Carbo‐Iron; Biological effect
• ISSN: 0147-6513; 1090-2414; 1090-2414
• DOI: 10.1016/j.ecoenv.2018.02.027

As nanoremediation strategies for in-situ groundwater treatment extend beyond nanoiron-based applications to adsorption and oxidation, ecotoxicological evaluations of newly developed materials are required. The biological effects of four new materials with different iron (Fe) speciations ([i] FerMEG12 - pristine flake-like milled Fe(0) nanoparticles (nZVI), [ii] Carbo-Iron® - Fe(0)-nanoclusters containing activated carbon (AC) composite, [iii] Trap-Ox® Fe-BEA35 (Fe-zeolite) - Fe-doped zeolite, and [iv] Nano-Goethite - ‘pure’ FeOOH) were studied using the unicellular green alga Chlamydomonas sp. as a model test system. Algal growth rate, chlorophyll fluorescence, efficiency of photosystem II, membrane integrity and reactive oxygen species (ROS) generation were assessed following exposure to 10, 50 and 500 mg L−1 of the particles for 2 h and 24 h. The particles had a concentration-, material- and time-dependent effect on Chlamydomonas sp., with increased algal growth rate after 24 h. Conversely, significant intracellular ROS levels were detected after 2 h, with much lower levels after 24 h. All Fe-nanomaterials displayed similar Z-average sizes and zeta-potentials at 2 h and 24 h. Effects on Chlamydomonas sp. decreased in the order FerMEG12 > Carbo-Iron® > Fe-zeolite > Nano-Goethite. Ecotoxicological studies were challenged due to some particle properties, i.e. dark colour, effect of constituents and a tendency to agglomerate, especially at high concentrations. All particles exhibited potential to induce significant toxicity at high concentrations (500 mg L−1), though such concentrations would rapidly decrease to mg or µg L−1 in aquatic environments, levels harmless to Chlamydomonas sp. The presented findings contribute to the practical usage of particle-based nanoremediation in environmental restoration. [Display omitted] •Four different iron-based materials were subject to ecotoxicological study.•Greater effect on algal cells was detected after 2 h than after 24 h exposure.•Strong shading effect was observed for FerMEG12 and Carbo-Iron® at higher concentrations.•FerMEG12 having highest Fe0 content induced the strongest negative biological effect.•Nano-Goethite affected Chlamydomonas sp. least.