Table 1.
Particle characterization of TiO2 suspensions used in the experiments of the present study.
Figure 1.
Mean immobilization (±SD; n = 6) of D. magna exposed to 2 mg/L TiO2 of different sizes.
White bars: ∼200 nm TiO2; grey bars: ∼100 nm nTiO2.
Figure 2.
Mean immobilization (±SD; n = 6) of daphnids after 72 and 96 h of exposure to nominal concentrations of 0, 0.5, 1, 2, 4 and 8 mg nTiO2 (∼100 nm).
Figure 3.
Dissipation of nTiO2 (∼100 nm) from the water phase.
nTiO2 was measured as 47Ti, at initial concentrations of 0.5, 1, 2, 4, and 8 mg/L nTiO2 (ISO medium; means ± SD; n = 3).
Figure 4.
Development of biological surface coating in a 96-h toxicity test at 2 mg/L nTiO2 in ISO-medium.
(A) 24 h, before 1st molting; (B) 25 h, about 1 h after 1st molting with arrow indicating renewed particle adhesions at filtration apparatus and the lower ventral gap; (C) 48 h; (D) 72 h; (E) 96 h; (F) ESEM-EDX picture of nTiO2 particle agglomerates colored in red on spine of D. magna following 48 h of exposure to, nTiO2 particles at 2 mg/L.
Figure 5.
Molting success of juvenile D. magna (age ≤6 at 0 h) exposed to 2 mg/L nTiO2 (∼100 nm).
Bars between 24 and 48 h on the left indicate the percentage of individuals passing the first molting, bars on the right, from 66 h onwards, represent those individuals passing the second molting. Black dots indicate the percentage of immobilized D. magna in the nTiO2 treatment.