fig4

Figure 4. TEM (A, D, G, J) and HR-TEM images (B, C, E, F, H, I, K, I) of nZVI reacted with Cu2+ (Reaction conditions: initial concentration = 5 mmol/L; nZVI dosage = 0.5 g/L; temperature = 25 ± 1 °C; initial pH = 4.0 ± 0.1; reaction time = 2 h. C: cuprite; G: goethite; HR-TEM: high-resolution transmission electron microscopy; L: lepidocrocite.