Effects of nanoparticles on Daphnia magna population dynamics

ABSTRACTSpherical TiO2 nanoparticles (npTiO2) were prepared by controlled hydrolysis of tetraethoxy orthotitanate under a nitrogen atmosphere. ZnO nanoparticles (npZnO) were prepared using hydrothermal methods. The crystal structure, chemical, thermal and morphological properties of npZnO and npTiO2 were characterised using Fourier Transform Infrared Spectrometer, enery-dispersive X-ray spectroscopy, X-ray diffraction, and scanning electron microscope techniques. The short- and long-term experiments were started with neonates taken from the same culture and laboratory condition. In the acute experiments, npTiO2, npZnO, and cocktail concentrations were applied. 96h-LC50 values were 1.8, 0.7, and 0.1 mg L−1, respectively (p < .05). For the chronic experiments, different npTiO2 concentrations were performed. 21d-LC50 value was 1.0 mgL−1 (p < .05). Morphometry became progressively worse in concentrations of more than 1 mgL−1 npTiO2. Neonate and young individuals were more sensitive to death because of their l...