Nanotoxicity modelling and removal efficiencies of ZnONP.

In this paper the aim is to investigate the toxic effect of zinc oxide nanoparticles (ZnONPs) and is to analyze the removal of ZnONP in aqueous medium by the consortium consisted of Daphnia magna and Lemna minor. Three separate test groups are formed: L. minor ([Formula: see text]), D. magna ([Formula: see text]), and L. minor + D. magna ([Formula: see text]) and all these test groups are exposed to three different nanoparticle concentrations ([Formula: see text]). Time-dependent, concentration-dependent, and group-dependent removal efficiencies are statistically compared by non-parametric Mann-Whitney U test and statistically significant differences are observed. The optimum removal values are observed at the highest concentration [Formula: see text] for [Formula: see text], [Formula: see text] for [Formula: see text]and [Formula: see text] for [Formula: see text] and realized at [Formula: see text] for all test groups [Formula: see text]. There is no statistically significant differences in removal at low concentrations [Formula: see text] in terms of groups but [Formula: see text] test groups are more efficient than [Formula: see text] test groups in removal of ZnONP, at [Formula: see text] concentration. Regression analysis is also performed for all prediction models. Different models are tested and it is seen that cubic models show the highest predicted values (R2). In toxicity models, R2 values are obtained at (0.892, 0.997) interval. A simple solution-phase method is used to synthesize ZnO nanoparticles. Dynamic Light Scattering and X-Ray Diffraction (XRD) are used to detect the particle size of synthesized ZnO nanoparticles.

Correlations in metal release profiles following sorption by Lemna minor.

Following the rapid uptake of contaminants in the first few hours of exposure, plants typically attempt to cope with the toxic burden by releasing part of the sorbed material back into the environment. The present study investigates the general trends in the release profiles of different metal(loid)s in the aquatic macrophyte Lemna minor and details the correlations that exist between the release of metal(loid) species. Water samples with distinct contamination profiles were taken from Nilüfer River (Bursa, Turkey), Yeniçaga Lake (Bolu, Turkey), and Beysehir Lake (Konya, Turkey) and used for release studies; 36 samples were tested in total. Accumulation and release profiles were monitored over five days for 11 metals and a metalloid ((208)Pb, (111)Cd, (52)Cr,(53)Cr,(60)Ni,(63)Cu,(65)Cu,(75)As,(55)Mn, (137)Ba, (27)Al, (57)Fe, (66)Zn,(68)Zn) and correlation, cluster and principal component analyses were employed to determine the factors that affect the release of these elements. Release profiles of the tested metal(loid)s were largely observed to be distinct; however, strong correlations have been observed between certain metal pairs (Cr/Ni, Cr/Cu, Zn/Ni) and principal component analysis was able to separate the metal(loid)s into three well-resolved groups based on their release.