Figure 4: TEM observation of U-containing colloids in porewater.
From: Mobile uranium(IV)-bearing colloids in a mining-impacted wetland
(a) Scanning TEM image of colloids in porewater at 15–20 cm depth at spot A that was filtered with 0.22 μm pore-size membrane; (b) the corresponding Fe (blue)/C (red) EDS map; (c) TEM image of colloids in the same sample; (d) HRTEM image of small crystallites; (e) SAED pattern obtained from similar colloids interpreted as a combination of trigonal Fe(OH)2 (red) and cubic FeO (green) phases. Point EDS analyses on similar colloids show low but statistically relevant U concentrations in association with Fe and C (Supplementary Table S1). Similar results obtained from other selected porewater samples are shown in Supplementary Fig. S4. Scale bar, 50 nm (a,b); 100 nm (c); 5 nm (d); 5 nm−1 (e).
